12 : (cadmium yellow) (PY37), raw sienna (PBr7), burnt sienna (PBr7), (cadmium orange) (PO20), burnt umber (PBr7), (cadmium red) (PR108), venetian red (PR101), quinacridone violet (PV19), ultramarine blue (PB29), cobalt blue (PB28), viridian (PG18), olive green [hue] The English painter Trevor Chamberlain is primarily a plein air painter, so his palette is designed to mimic the range of colors that appear in naturally lit landscapes.
Chamberlain prides himself on a traditional approach to pigments and palette design, preferring for example the softer cobalt blue to the more aggressively staining iron blue or phthalocyanine blue. This attitude explains the similarities between Chamberlain's palette and the classical palette, for example the preference for earth paints rather than saturated red, orange or yellow paints. (Chamberlain says that three cadmium paints are "held up my sleeve" for bright color accents or to render the occasional manufactured or painted objects, such as those famous English phone booths.)
Including the optional cadmiums, Chamberlain spans the warm side of the hue circle with eight paints. The painting strategy inherent in the paint selection is to render light primarily through value (lightness). Thus, the iron oxide ("earth") pigments are dark and muted in masstone, but become brighter, more transparent and more saturated as they are diluted. Raw sienna shifts from a yellowish brown to a pale medium yellow, burnt sienna from brown to a dull orange, venetian red from brick red to a glowing, fleshy pink, and olive green from a dull green to a pale greenish yellow. These pigments retain their brighter color across lighter values, which mimics the way increased light intensity makes colors both more saturated and lighter valued. And the cadmiums can be used to slightly increase the chroma of the iron oxide pigments, as appropriate, to indicate passages of maximum light intensity.
The most saturated colors are dark hues ultramarine blue and quinacridone violet which also become less saturated and softer as they are diluted. Chamberlain only uses two blue pigments, one dark (ultramarine blue) and the other mid valued (cobalt blue). Both display subtle pigment texture, and create a surprising range of atmospheric effects in washes, especially when muted with an earth color.
His painting style also highlights the textural effects possible with the earth palette colors, cobalt blue and viridian, which he accents through wet in wet application, sponging and lifting of color. (Note that he gets excellent substitutes for cobalt cerulean or cobalt turquoise as a mixture of cobalt blue and viridian.) Viridian or quinacridone magenta pull the two blues toward turquoise or violet, adding subtle texture of their own. All mixed purples are relatively dark and dull, making them perfect for shadow colors.
The choice of olive green (in Winsor & Newton, a pale convenience mixture of phthalo green and yellow iron oxide) is unusual permanent sap green is darker, more saturated, and more commonly used. The main green on the palette, viridian, which is a granulating and moderately saturated blue green, provides sufficiently bright green mixtures with cadmium yellow, and more muted mixtures with raw sienna or burnt sienna. The choice of the less saturated viridian and olive green indicates that Chamberlain wants to keep his greens muted. The darkest, dullest greens can be mixed with raw sienna and ultramarine blue.
Near black mixtures are available by mixing burnt umber or burnt sienna with ultramarine blue, or quinacridone violet with viridian. These darks dilute into subtle and velvety grays, as illustrated by the trees in the painting above.