This is a modern concept. Classical painters such as Claude or Poussin were known for their careful color balancing and use of color for symbolic purposes. But their design vocabulary and conceptual grasp of color were limited by the range of available pigments. Before the Industrial Age, institutional or occupational costumes and limited dyes and fabrics made color harmony principally a problem of choosing materials: colored stones, colored gems, colored minerals, colored dyes.

But after c.1780, the proliferation of industrially created colorants allowed a wider and cheaper diffusion of color into wallpapers, ceramics, textiles, printing inks, architectural paints and artists' colors. This awakened the fashion sense that some color combinations were more pleasing or striking than others. This transition appears in the founding texts of "color theory" by Michel-Eugène Chevreul, where the analysis of color in the abstract grew out of the imperative to understand textile manufacturing problems created by brighter synthetic colors and more demanding consumers.

Even in the 19th century, however, color harmony was typically an informal principle. The French painter Eugène Delacroix empirically worked out color designs by painting his mixtures on strips of canvas that he hung on his studio wall for careful study. If theory was wanted, most painters simply used the complementary pairs of the secondary color wheel — in those days defined as red/green, orange/blue, yellow/violet — and these complementaries remained the norm even in the paintings of "scientific" neo-impressionists such as Georges Seurat, who knew from reading Ogden Rood that red was not a visual complement of green and violet was not a complement of yellow. The artistic application of color science was still not very rigorous.

Rigor (or something that was supposed to look like rigor) came in the early 20th century. European artists focused seriously on color harmonies and the (entirely imaginary) analogous relationships between color and music or color and emotions. These studies were linked to a revived interest in Goethe's color theories and to a mystical or ritualistic emphasis on "primary" colors. Even today, "color theory" clings to the assumptions and aims made explicit during this period.

The figure shows a typical offshoot of this effort: a color harmony interpretation of Goethe's six pointed color star, by the Bauhaus trained Yale University design professor, Josef Albers (1888-1976).

josef albers' "moral" color harmonies (1963)

 
Albers has reversed Goethe's color star and transformed it into a color triangle by folding the secondary color points inward (to mimic the trichromatic mixing triangle of color science). He then filled the remaining three spaces with mixtures of the "primary" and complementary colors, the primary dominating the mixture. (All "color theory" has this manner of childlike simplicity in the way it manipulates color concepts and color demonstrations.)

The "psychological" interpretation of these color harmonies, presented as bands or sections within the triangle, follows the example set over a century earlier by Goethe's moralizing color associations ("scarlet is pleasing to impetuous, robust, uneducated men"). But the new interpretations were developed by the consensus color associations of 20th century European artists and intellectuals.

The most striking aspect of this kind of harmonic diagram is its radical simplemindedness. A comparison of this color triangle either to the natural spectrum or to the sheer variety of painting pigments may open your eyes to the brutal disfigurement that this scheme inflicts on the natural experience of color. The confused status of complementary colors in different color models shows how arbitrary these abstract color systems really are. Brutal, abstract, arbitrary ... like the penal codes of a totalitarian regime.

In some cases these rules create a predefined symbolic code. They provide a way for an artist to say something that has already been said to an audience that expects to hear it. As such "color theory" is purely conventional, and coercive in the mild sense that it restricts the range of an artist's expression and limits the audience that can interpret it. That is often its goal, because that is the only way to endow color with communicative significance.

The select audience is a particular consumer market segment, social group or social class, and the class dimension of "color theory" comes through clearly in the emphasis on character terms or "color personalities" ascribed to individual colors and color combinations: red is male, green is peaceful, blue is mystical, pastels are modern, taupe is trendy, and so on. The artist first conceives a design goal as a "moral" state — for example, "this will be a serene room" or "I wish to paint a serious picture" — then uses the theory to identify the appropriate colors or color harmony, and from there proceeds to the selection of colored fabrics or paints. (Colors have even been linked to male or female essences, to times of the day, to geometrical forms [yellow is a triangle], to musical intervals, and so on.) But what about "playful," or "nurturing," or "days of the week," or any other attribute not in the color symbol vocabulary? Those represent design issues that were irrelevant to the viewpoint of the male, technophilic, overintellectualized, mystical, humorless and misguided group of artists who invented the color codes in the first place.

Of course, if the viewer does not recognize this culturally dependent color symbol code, believes in a different code or comes from a different culture, or simply approaches color experientially rather than intellectually, then the symbolic aspects of "color theory" become irrelevant and impotent.

To refute the charge that their color codes might be arbitrary, "color theorists" argued that there are universal physical or psychological reactions to different colors. Colors must have a universal significance because they arouse our physiology or psychology in consistent ways: green calms and red excites, yellow makes cheerful and blue makes introspective. These hypotheses have been extensively tested by academic color research from around 1890 up to the present day; Bauhaus designers even sent out survey questionnaires to measure the collective emotional associations assigned to colors. The net result of this research? Just hundreds of publications to show that consistent physiological effects of color don't exist. (One well established finding: there are beneficial effects from white light exposure in the treatment of SAD or seasonal affective disorder.)

Lacking consistent proof for the physiological or psychological power of color, "color theorists" fell back on the idea that "primary" colors embody transcendental qualities of light or nature or spiritual being. (The tactic here is an old one: lacking empirical proof, fall back on religion.) Some "color theorists" of the 19th and early 20th centuries linked the "primary" triad to the Holy Trinity. On those imaginary cornerstones rigid geometrical or symbolic models could be rebuilt; and within those models, the "primary" triad acquired a stupefying magical or pseudoreligious symbolism. Once humans get rolling on an allegorical or symbolic system, free of any concern for the facts, there is no end to their ingenuity.

The real problem? "Color theory" then becomes detached completely from the materials of color making or the facts of color vision. Color is an experience, a perceptual phenomenon, yet "color theory" talks about "blue" or "yellow" detached from any material circumstances, as abstractions or absolutes. There is an implicit appeal to the scientific premises of our technological culture, the 19th century expectation that all aspects of human existence could be (ought to be) reduced to simple universal principles: color obeys "laws." In fact, color is not like gravity, for the simple reason that living things are not the same as inanimate objects and neurobiology is completely different from physics. As I've shown elsewhere, "primary" colors are either imaginary or imperfect, they are either "colors" that are invisible (and arbitrary), or they are represented by physical colorants that, in the case of paints, can behave in surprising and erratic ways. It seems to me evident that most of the great painters, the painters I most admire, anyway — Titian, Caravaggio, Velàzquez, Vermeer, J.M.W. Turner, Monet, Degas, J.S. Sargent, John Marin, Fairfield Porter — there is an incredible sensitivity to and masterful handling of the color materials, the paints themselves, and the many amazing effects they can produce on the eye.

A related problem is that "color theory" is careless about controlling hue, lightness and chroma as separate sources of color effects: violet against yellow, or orange against blue, differ significantly in lightness and chroma as well as hue. When each colormaking attribute is tested separately, the same contrast demonstrations show that lightness and chroma have a much stronger contrast impact than hue, which by itself has a weak effect.

As John Gage points out, the surest antidote to a dogmatic "color theory" is art history. There simply are no consistent color meanings in world art, no consistent methods for handling color materials, no universal optical effects embodied in painting techniques. Several movements in modern painting — for example the Pre-Raphaelites, Cubists and Fauves — used "shocking" or "forbidden" or "wild" color schemes to break out of conventional color codes and use color to say new things. After a brief period of argumentative turmoil, these practices became the new color norms, the new color codes, and color dogma rolled on as complacently as before.

Colors cannot be assigned objective meanings because cultural expectations and experience play a large role in a viewer's response. This is a good thing: it means the symbolic power of color is continually renewing itself, adapting to the range of color experience in a culture at any historical moment. "Color theorists" perversely want to fix this symbolic power once and for all as a universal language of color, a kind of chromatic Esperanto. Their theories (and Esperanto) haven't gained wide support because people much prefer to use the color codes (and color terms) that grow from their culture and social situation. Case in point: most German and French color symbolists claimed that red is a "sensual" or "earthy" color. The Russian Wassily Kandinsky used red as the "spiritual" color. Why? Well, in rural Russia, the "red corner" of devout peasant homes — that is, a corner actually painted bright red — is where religious icons were displayed.

"Color theory" describes color as an external fact with consistent properties, — when all the available evidence about color suggests exactly the opposite: color experience is completely dependent on the physical, visual, artistic and cultural context. Color is not an essence that inspires us directly, like a holy ghost or a jolt of electricity. Abstract color ideas divert attention from the material presence and power of a work of art. Artists paint with paints, not with colors: paint is on the paper or canvas, color is in a viewer's mind.

A final problem, as explained in the page on tonal value, is that the perception of pattern and form has a powerful effect on apparent colors (and apparent values). Vision continually interprets color as part of three dimensional forms in an illuminated life space. Approaching color through the experience of flat color areas is a simplification useful only to a certain style of painting and crafts manufacture. It hardly represents the full range of our color experience — and that is the problem with "color theory" in general.

Put simply: "color theory" developed through contrasting colored squares may, in the end, only help you to understand ... colored squares.

1. There are important constancies in the visible world, such as linear perspective, the contrast of light and dark, or the behavior of light. If the artist understands these realities, he can produce more convincing or impactful visual representations.

2. There are fundamental properties of the retinal image, including the opponent perception of colors, optical artifacts, afterimages or visual fusion, that arise from the workings of the eye. If the artist knows what these fundamental properties are, he can use his materials to enhance or simulate them in an artistic image.

3. Two dimensional images of a three dimensional world are ambiguous and complex; vision must rely on basic visual cues or strategies of interpretation, such as depth cues or the reliance on edges and textures to define objects, to make sense of what we see. If the artist understands these basic cues or strategies, he can use them creatively to control how viewers will interpret an artistic image.

4. There are universal meanings attached to visual signs that originate in our psychological or biological relationship to the world: a vertical line represents strength and a horizontal line repose; red signifies passion and blue relaxation. If the artist understands these deep visual codes, he can build a universal symbolism into his image.

These topics are usually brought into the art academy, with most of the science left out, through the study of elements of design, principles of composition or the symbolism of art. My aim is to go back to the science in order to clarify the basis of those academic principles, with the expectation that other resources remain undiscovered or unrecognized.

There needs to be a cleansing of art theory and "color theory" by anchoring every aspect in perceptual or cognitive science.

When this cleansing is done then new principles need to be added from practical experience, from psychology, from experimental esthetics.

Principles must be formulated tactically, as tools useful in specific situations, so that they do not encumber the artistic strategies on which styles and innovations are based. We must achieve a vision of art that releases rather than encumbers creativity.

two programs for linking art to vision science

 
In all aspects of artistic "color theory" there are usually four important questions to get answered:

•  The most important is to clarify exactly what is meant by a specific term or concept, or what actually is the goal of an artistic process, or what exactly are the desirable attributes in artistic materials. This is done by surveying the consensus language and common practice of professional artists.

•  Then we must explore how these terms, processes or materials relate to the domain of factual and theoretical knowledge in vision science, materials science, business realities, conservation techniques, and so forth. We must anchor the artistic practice in the way things really are, by deferring to science, fact and empirical demonstration.

•  We then can use the scientific information as a corrective by which the terms or goals can be expressed more precisely, the goals limited, expanded, redefined, or identified as subjective or cultural and therefore arbitrary (the "meaning" of colors, for example)

New Painting Codes. The outcome of color research should be two: to show how far painting styles represent painting codes, and to identify in natural vision new features for new painting codes.

Gombrich described the invented and conventionalized nature of art. This implies that all art paintings by an artist can be distilled to a system of specific rules applied to the manipulation of specific materials; and the "style" of the artist would be reducible to a minimum or characteristic set of rules common to all.

The analogy here with a game such as chess is exact.

Problem is that this leaves the value of art in its "message". But I think art works by exemplification or showing, and what it shows is simply a group of goals or standards (values) applied to the manipulation of materials. These largely fall into the domains of skill, appeal, symbols and topic. Skill for example is exemplified by accuracy or control both in materials and in the other values; appeal by color or line or gesture, symbol by icons or optical images, and topic by historical themes or decorative motifs.

In this way the research cleansing would lay the foundation for a critical language that would allow description or evaluation of any work of art in terms that would be directly comparable with any other description and with viewer evaluations of the work of art. This could lead both to new and more effective painting styles and more aggressive exploration of existing painting styles.

The difference between talking because it creates an aura of structure and choice and control, and the process of discovery which is difficult and painful.

Many times I have emphasized that color effects in the natural world are not detached from material circumstances. I have also hit repeatedly the idea that color can be analyzed or described in the abstract, either as an abstract mental quality or as a quality independent of substances.

The distortions created by color abstraction include the spiritualizing of color and ignoring the ways that colors affect one another in context.

Ignoring the material qualities leads to marketing names and ignoring problems of permanency and lightfastness.

Ignoring the material qualities leads to an insensitivity with color materials and their properties.

Yes, there is. For the past 400 years, the drug of choice to combat those headachy symptoms of color complexity has been the "primary" color scheme. Ah ... what relief! Three paints are all you need to mix any hue! And thanks to intense modern pigments, convincingly too: the "primary" triad palette can be very effective in the hands of a skilled artist such as Jean Grastorf.

The 18th Century and Reification. After much study of the "color theory" literature, I came to a conclusion I hadn't expected and didn't like:

all "primary" color ideas taught by modern "color theorists" represent 18th century color mixing ideas.

My objection is not that 18th or 19th century ideas are bad, just that 18th or 19th century ideas about color are wrong, and from that misguided tree have come many misguided apples of misinformation.

Contemporary "color theory" was developed during the century of Newtonian color confusions and became dogma in the 19th century. I critique some of these ideas in my reviews of books by J.W. von Goethe, Michel-Eugène Chevreul, Ogden Rood and Michael Wilcox, and in my comments on Newton's color circle, artist's color circles and the split "primary" palette. But as a summary statement of the misleading concepts, here is the color catechism preached by English architect Charles Hayter (1761-1835):

First — That Yellow, Red and Blue, are entire colours of themselves, and cannot be produced by mixture of any other colours. ... Secondly, Yellow, Red and Blue, contain the sole properties of producing all other colours whatsoever, as to colour [hue]. ... Thirdly — Because, by mixing proper portions of the Three Primaries together, black is obtained, providing for every possible degree of shadow. Fourthly — And every practical degree of light is obtained by diluting any of the colours ... by the mixture of white paint. Fifthly — All transient or prismatic effects [of light mixtures] can be imitated with the three Primitive Colours, as permanently considered, but only to the same degree or compensation as white bears to light. Sixthly — There are no other materials, in which colour is found, that are possessed of any of the foregoing perfections. ["A New Practical Treatise On the Three Primitive Colours," 1826]

These pronouncements are a blend of special pleading, false reasoning, and ignorance of the facts. The first point claims that the color yellow in paints is an "entire [pure] colour" of itself, when in fact yellow always consists of both "red" and "green" reflectance. The second point, the "unmixable from other colors" proof of "primary" colors, is only valid in the limited sense of color as hue; this claim is refuted in the next section. The fifth point uses an obscure evasion ("as permanently considered but only to the same degree or compensation as white bears to light") to claim that "primary" paint color mixtures duplicate light mixtures, which is simply false. The sixth and first points suggest that Hayter considered color in subtractive color mixtures only, disregarding the color mixtures in light.

Hayter's example invites us to add a seventh "primary" color principle inherited from the 18th and 19th centuries: All "primary" color dogma is based on false reasoning or false information. The false reasoning appears in the reification of "primary" colors — the belief that abstractions must be real, and therefore can be used to explain things outside the limited problem they were originally used to answer.

I've explained elsewhere why the concept of "primary" colors is only a useful fiction, and why "primary" colors must be either imaginary or imperfect. A limited number of "primary" colors can be a cost effective method of color production (in video, printing or painting) or a mathematically elegant way to predict additive color mixtures and apparent color matches from an idealized retina. In those situations, as shortcuts or fictions adapted to solve specific problems, "primary" colors are harmless because they are specific solutions to a specific problem.

The flaw in artistic "color theory" is that the reasoning goes in the other direction: the various limited, practical solutions that use "primary" colors have led "color theorists" to leap into the imaginary realm of "pure" color, declare that "primary" colors are real, and use "primary" colors to explain every aspect of color experience. The result is that "primary" colors degenerate into the rigid thinking that is inadequate to describe color facts and too limiting to guide artistic intuitions. In fact, subtractive color mixing can never be precise or geometrically simple and, in the abstract, doesn't even exist!

I put "color theory" and "primary" colors in quotes because "color theory" and "primary" colors do not signify anything theoretical or primary. The "theory" distorts painting experience more than ignorance does, and the "primary" color explanations distract the painter from learning the quirks of color vision, the peculiarities of actual pigments and paints, and the adventure of exploring color experience without labels or dogmatic ideas.  

1. the matching surface color can be produced by wavelengths from a limited band of the spectrum

2. it is possible in theory to produce the necessary chroma in the narrow reflectance band from the subtractive mixture of two overlapping reflectance curves, and

3. two pigments actually exist that come close to the required overlapping reflectance curves.

Point 1 has to do with the fact that subtractive paint mixtures destroy reflectance, so paints cannot create broad bands of high reflectance through mixture. Point 2 stipulates that the desired narrow band of reflectance is not so high or sharply defined that it cannot be produced by subtractive mixture. Point 3 says you can't mix a color if you do not have pigments with the right reflectance curves.

Now, instead of resorting to spiritual or mystical explanations for color behavior, we can ask whether the subtractive "primary" colors satisfy these three conditions.  

Yellow. Let's start with the subtractive "primary" yellow, which is the color that seems unquestionably fundamental. Every painter has had the experience of mixing an intense deep yellow and a bright yellow green only to come up with a dark grayish brown instead of the desired lemon yellow.

In surface colors, we can only produce a saturated yellow color through a very broad, high reflectance across both the red and green parts of the spectrum. There is no such thing as a dark yellow color: the lowered lightness produces a large contrast with the available illumination, and this turns the color to a dull green, tan, brown or gray. There is also no such thing as a yellow surface that reflects only in the yellow wavelengths: its reflectance again would be so low in comparison to the illumination that it would be a grayish brown.

Yellow is fundamentally a light valued color — in fact, it is the lightest valued hue in the color wheel. (The link between the hue and lightness of yellow is a specific example of the effect of the unsaturated color zones, explained above.) But this means yellow fails the first requirement for subtractive mixture: the color cannot be produced by a narrow band of spectral reflectance.

In fact, a yellow hue can be mixed — and very easily — from two other paints, for example from a yellow orange (like benzimida orange, PO62) and a yellow green (like a permanent green light). The green provides reflectance in the "green" and "yellow" sections of the spectrum, with relatively little in "red"; the orange provides reflectance in the "red" and "yellow" but not in the "green" wavelengths. When these hues are subtractively mixed in paints, they cancel each other out everwhere except in the "yellow" wavelengths.

mixing "yellow" from an orange and a green paint

 
But this mixture doesn't look yellow (in fact it looks sadly close to gray), because the mixture destroys the luminosity of the color and with it, the bright yellow appearance. So even though yellow does satisfy the second and third requirements for subtractive mixture, and yellow in fact can be mixed from other colors, failing the first requirement dooms every subtractive mixture.

It's worth mention that the same problem arises if we try to mix an orange color from "primary" yellow and magenta paints. The perception of orange also depends on high luminosity, and the orange mixture is also typically darker and duller than a true orange, which usually makes it appear to be a brown close to burnt sienna. So why isn't orange also a "primary" color? I think the answer is: because this is inconsistent with the "color theory" preconception that there must be only three "primary" colors.  

Magenta. Surprisingly, at first glance it appears that all of the subtractive requirements can be met in a "primary" magenta mixture.

The color magenta remains relatively unchanged across reduced levels of color reflectance, so it can be produced by narrow reflectance in the spectrum. This reflectance is actually split across the two ends of the spectrum, because magenta is an extraspectral hue that does not occur in a prismatic spectrum and can only be produced by the mixture of "violet" and "red" wavelengths. In theory we could mix that kind of reflectance from a blue containing some red reflectance, and a red containing some blue reflectance. And in fact we have two pigments (if not more) that fit those requirements very well: ultramarine blue (PB29) and quinacridone red (PR209).

mixing magenta from a blue violet and a deep red paint

 
So it turns out that we can mix magenta from two other paints. But, if we actually make this mixture, as a magenta it looks disappointingly dark and dull. This is because two hidden problems compromise all magenta pigments and mixtures.

The first problem: magenta pigments always stimulate the G cone to a significant degree, making the color relatively dull because all three cones are stimulated at the same time. The problem arises in the eye, in the overlap between the R and G cone sensitivity curves. This is obvious in the reflectance of quinacridone magenta (PR122, shown below), which is probably the most intense pure magenta pigment available in watercolors. Anything that affects a pure magenta pigment will also affect a magenta mixture.

green reflectance in a magenta paint (PR122)

 
We could try to eliminate this problem by limiting the reflectance to the extreme "red" and "blue violet" ends of the spectrum, where the G cones are least sensitive. But now we run into the second problem: these are also the darkest (least luminous) regions of the spectrum, so the resulting color would appear very dark, and this loss of luminosity would also destroy the color's chroma and mixing power in paints.

These problems are of a completely different kind than the problems that arise in mixing yellow, so the fact that yellow and magenta are both difficult to mix is no proof whatsoever that they share any fundamental, "primary" purity or uniqueness.  

Cyan. According to "color theory," cyan should also suffer from the same problems as the other "primary" colors. Yet those problems just don't seem to arise.

The cyan color can be created by a narrow to broad band of "blue" and "green" reflectance, and this reflectance matches the overlap between blue and green pigments. And in the mixing experiments designed to test the color wheel, I found that there is no abrupt change in chroma or lightness of blue green mixtures around the cyan (PB15) point on the color wheel, in the same way there is a loss of luminosity around yellow or a loss of chroma around magenta: the subtractive color mixing antagonism is simply not an issue.

In addition, blue green is near the center of the visible spectrum, so (unlike blue violet or deep red) blue and green pigments have the potential to be relatively luminous. But in fact there is a problem with available cyan pigments, which are rather dark valued (like phthalocyanine cyan, PB17), or reflect a substantial amount of "red" light (like cerulean blue, PB35).

The culprit may be limitations in contemporary chemistry or constraints in the atomic basis of color. In any case, we can mix a mid valued cyan from two other paints: cobalt teal blue (PG50) and phthalocyanine blue GS (PB15:3) . If more intense, lighter valued pigments are ever developed in the turquoise and middle blue parts of the color space, even brighter cyan mixtures will be possible.  

"Primary" White (and Black?). Cannot get full range of color without a source of white. Example, mixing paints in a bowl.

White is always there, but in the interests of theory it is swept under the rug by assigning it to the background or, quaintly, to "the light shining through the pigment like a stained glass window."  

"Primary" Orange, Violet and Green. The final problem is that many other pigments exist that cannot be mixed from other pigments (colors). For example, in watercolors, isoindolinone yellow deep, pyrrole orange, pyrrole red, dioxazine violet, ultramarine blue, phthalo blue, and phthalo green are all more saturated than any mixture of two other pigments to a matching hue and lightness. This is especially obvious if you limit your matching mixtures to combinations of the three subtractive "primary" colors — try it yourself and see!

The same problem appears in all color media. For example, new color television technology uses specialized software to adapt the standard three phosphor gamut to include a fourth, blue green "primary". The result is an obvious and desirable increase in the apparent quality of the color picture. Yet no one has claimed cyan as a fourth additive "primary" color.

Conclusion. I've just demonstrated that the reason "primary" colors are unmixable has nothing to do with their function as "primary" colors in subtractive color mixing. "Primary" colors work in subtractive color mixing because they all stimulate two cones but not the third. Any problems in mixing the colors from other paints are irrelevant to this double stimulation requirement. Several pigments produce colors that are unmixable from any other known pigments, but this does not make them "primary" colors either.

Mixture is inherently impossible for yellow because our visual system ties its hue to its luminosity, and luminosity is destroyed by darkening subtractive mixtures; is disappointing for magenta because of obscure problems with G cone stimulation and darkness at the spectrum ends; and is technologically limited for cyan by the low chroma of available blue and green pigments. Three different "unmixable" colors, three completely different color mixing explanations.

The relationship between the mixing power of "primary" colors, and the fact that they cannot be mixed from other colors, is purely coincidental. And this coincidental "fact" only applies to one "primary" color, and was falsely asserted as true for the other two.

 
The 18th century explanation was relatively straightforward: there were three "primary" colors of light, which in their pure form appear as the colors yellow (Y), red (R) and blue (B). In vision these three different colors of light enter the eye in different proportions, where they affect the three types of color receptors adapted to them. The combined responses of these receptors "mix" the three "primary" colors in exactly the same way as paints mix.

The difference between additive and subtractive color mixing was not clearly understood, so the importance of evaluating the illumination color and intensity separate from the surface color was generally ignored. Unusual color effects, such as complementary colored shadows and adaptation to strongly colored light, were all swept under the vague notion that the eye "strives for balance" or "seeks harmony" in its color relations. This mixed and adjusted sensation is sent directly to the small part of the "sensorium" or conscious experience where color perceptions appear; and this results in the color experience.

Under the cover of a few cosmetic changes, such as substition of the visual "primary" G for the subtractive "primary" Y, this is essentially the same "color theory" taught in most art schools today and believed by most artists. Art has made no significant advance in its understanding of color since the 18th century.

The modern color explanation is more complex, but this complexity is still less that what is required. The difference between additive and subtractive color mixture is clearly understood, and the fact that additive mixture is generally the same across all types of light, while subtractive mixture varies considerably depending on the type of substances that are mixed.

In the perception of surface colors, the illumination and surface spectra combine subtractively, which means both must be measured in order to understand the actual wavelengths of light reflected to the eye. The luminance level is important, especially at extremely low or high levels, as are the colors of the areas surrounding the surface color. From these outputs the visual system performs several transformations of the color information, first translating the three "primaries" into the four unique hues (plus a white/black or luminance channel), then, at some late stage, into the three colormaking attributes. This minimum of information, already discussed in previous pages, allows a satisfactory prediction of how the retinal light receptors will produce a color experience given the available illumination and background color.

However, during these transformations many other processes, discussed later, also significantly affect color appearance. Most important are luminance adaptation, which extends from the iris to the higher levels of the brain, and chromatic adaptation, which extends from the retina to the brain. The color information is also adjusted further to weave a cohesive image of the world. These adjustments include simultaneous contrast, visual fusion, edge sharpening, area filling or visual completion, the perceived spatial relations and illuminant direction of the surfaces in view, memory color (beliefs as to the color the surface should be), conventional labels attached to color experience, and so on. These cognitive or judgmental activities involve most of the brain, and all must be included in any explanation of color experience.

The situation can be summarized this way. In the 18th century (and among many artists today), "color" is something transmitted more or less directly from surfaces to the eye and from the eye to the brain, thanks to the cohesive linkage provided by three "primary" colors that remain constant throughout the whole process. This process can be reversed — a color from the brain through the eye to a page, via a "primary" color mixture of paints — which means that colors can be "copied" from nature into paintings.

The modern view is something different. Color is an experience that is profoundly affected by many dimensions of the physical world and by receptor and cognitive processes. Nowhere, at any step of the process, do absolute or unchanging "primary" colors enter into the explanation. This makes the "copying" of colors from nature into a painting implausible or impossible, and makes the creation of a painting highly dependent on the specific materials used to create color and the specific color relationships in the painting itself.

Although it is a more complex explanation, I hope to show you that the modern understanding of color has two enormous benefits. It clarifies the actual problems involved in the skill of painting, and it helps direct the painter to the best solution to those problems.

Programs in lightfastness testing.

Empirical demonstrations of color effects.

Lack of historical awareness.

Partnership with campus perceptual and cognitive psychologists.

This position is usually expressed in three ways. Probably the most frequent position is simple ignorance, indifference or laziness. These slackers paint what they see and see what they paint; whatever they mix is fine for what they do, and if the design or color is bad they just throw the painting away. Color theory is something like a tax code or market regulation that just gets in the way of their business, or one of those beach warning signs about tides and rocks that only get in the way of their summer fun. If they can work around it, or swim past it, they do so.

Slackers include many very talented and productive artists, and for them the fault is not learning color theory but not translating their skill into advice that can be passed on to others. When color theory confirms their practice, this proves that it is irrelevant; when color theory contradicts their practice, this proves that it is incorrect. Grounds, either way, to ignore it.

This is not a personal failing but an occupational trait. Artists are craftsmen with materials, and if they experiment with materials they do it to solve a specific process problem, not to derive a general principle. They are not didacts or theorists, and putting their process into words and teaching it to others would be a huge diversion from their painting practice. And it is not something they can do well, if at all.

This is especially true of art school instructors, which brings me to the second category of reactionaries: the hacks. Hacks have incorporated the dogma taught to them by their teachers and pass it along unchanged to their students. The geneology here, generation to generation, goes all the way back to the 18th century.

Hacks have learned that color is a certain domain defined by explicit principles, and the task of the student is to learn those principles. "Primary" colors, color wheels, complementary contrasts, a whiff of Goethe, a heavy dose of Bauhaus, a little notan and lots of "color meaning" — the hack syllabus is immediately recognizable.

Finally, there is the fringe of individuals whom I call the whack jobs. It is a cultural fact that color attracts a certain kind of theoretical, abstracting mind not much different from conspiracy buffs and religious fanatics. They have their all explaining, all encompassing and all reductive view of things and no facts or practical alternatives will get in their way.

For many of these color theory enthusiasts, the basic equation is extremely commonplace: talking is easier than painting. Whether they are privately reading about color rather than painting, or posting color theory screeds rather than painting, or conducting arcane color mixing experiments rather than painting, they are doing something that is not painting.

For these folks there is a very simple question: how does this discussion relate to a specific painting problem? Many are brought up short to realize, well, they don't have a specific painting problem. And those that do are led to talk about color in practical, contextual terms, rather than to debate generalizations that treat color as an abstraction.

A few are passionate defenders of their individual faction of color theory, and are eager to ignite a debate around it. I've found the best recourse is simply not to engage.

I have to admit that my typology is rather like George Carlin's classification of people into stupid, full of shit or fucking nuts. And it was only by using Carlin's filter on my own color studies that I came to put much of it in perspective.

I cannot by any stretch be called a slacker, but I have certainly fallen into the camp of hacks and whack jobs. As someone who recycled scientific ideas about color without really understanding them or without clearly understanding how they apply to artistic problems, I have been a hack. And as someone who felt personally empowered to displace conventional "color theory" with my own I have certainly resembled, if not become, a whack job.

I think my salvation has been my persistent efforts to paint better, and to understand why painting progress occurred. And this, it seems to me, has to be the touchstone of a modern color theory: all students should prosper with it.

Some of that confusion has been my own. I realized how frequently I use color terms or color concepts in a kind of trance or dream, seeing the concepts without actually grasping them.

In many cases, I adopted that confusion from the sources I consulted. Academic studies recognize the unusual nature of the unsaturated color zones, and some have even tested whether brown, maroon or pink are "fundamental colors" in the color space in the way red, green, yellow and blue are. (Apparently they are not.) But none seem to have pointed to the peculiar "sideways" saturation coding of reflected colors as the fundamental qualitative difference between warm vs. cool colors. The eye is not a heat receptor: warm colors are not "warm like fire" as many "color theorists" will tell you — but because they are "brimming with light"!

Artists have been remarkably perceptive about color. Leonardo da Vinci identified the four unique hues over four centuries before the scientist Ewald Hering did. And long before artists had the terminology to talk about chroma in colors or value scales, they controlled these effects through the technique of grisaille underpainting — glazing transparent colors over a background of light and dark gray, essentially mixing the colors with gray or near black. Artists weren't interested in talking about color, but in developing practical techniques to control color effects. Artists have learned about color through experience and quite a lot of experimentation.

This is the heart of my strong distaste for "color theory" — it replaces color experience with color talk, and inhibits color experimentation by teaching simplistic schoolroom "color facts." Artists are experimentalists with materials and ideas; they use colors the way engineers use plastics, or scientists use mathematics — to realize whatever they can imagine.

Explanations of color should, I believe, stick close to the methods used to explore color, so that explanation leads directly back to exploration. My often tedious explanations of color phenomena are intended to make this link explicit. My view is that art is fundamentally a kind of meditative or physical practice in which you teach yourself to see. I have attempted to describe what I feel are the psychological consequences of artistic practice, but the means to those ends are always personal exploration — endless exploration.

The good news is that the color learning tools available to artists today have never been more powerful: computer graphics programs, spectrophotometers, digital cameras, process color manuals, color scanners, digital art reproductions, intense pigments, spreadsheet programs to plot and graph color relationships. It's intriguing that most art departments are eager to encourage "digital media" as an art from, but neglect it as a tool for artistic training and exploration. Color scientists are more frequently using computer color monitors to study color vision — artists can and should do the same.

I've demonstrated all these tools on this site, to teach you methods of exploration and the confidence to trust in your own curiosity. I also recommend color theory books that describe other tools — "color tops" and exercises with colored paper — useful to color learning.

Personal experimentation is the only way to break out of the circular explanations of today's color theory. It's the only proven doorway to a genuine understanding of color. And this experience is universal, the process by which artists outgrow "color theory" toward an intuitive understanding of color effects.