typical reflectance curves for red orange to red pigments

 

saturated "spectrum" red
A "spectrum" red pigment reflects light primarily from the "red" end of spectrum, and reflects either very little "blue" light or "blue" and "green" light in equal proportions. The hue ranges from red orange or scarlet red to deep red. Paints made with these pigments appear brown if darkened, hue shift toward yellow when diluted, and mix relatively dull purples with blue paints.

 

saturated "blue" red
A "blue red" pigment contains more "blue" than "green" reflectance, even when the hue is the same as a "spectrum" red. Paints made with these pigments appear somewhat maroon if darkened, hue shift toward magenta if diluted, and mix relatively brighter purples with blue paints.

 

cadmium red light (scarlet)

cadmium red medium (red)

cadmium lithopone red deep

pyrrole red

 

quinacridone red

quinacridone pyrrolidone

unsaturated "spectrum" red

venetian red

quinacridone maroon

 

unsaturated "blue" red

perylene maroon [lightfast]

alizarin crimson [not lightfast]