th go hand in hand. Jan Vermeer's paintings also show a career shift in color design, from a red/green contrast in his earlier paintings to a more austere, atmospheric yellow/blue contrast in his later works. The palette by Lucy Willis is a good example among contemporary watercolorists.
However, the fact that artists define and use the warm/cool contrast in different ways shows that there is no such thing as a universally "warmest" color or "coolest" color, either. Color attributes such as lightness, hue or chroma are inherently defined by context in particular, by the chromaticity of the light illuminating the objects in the image so the best choice of warm or cool colors will depend on the design goals or painting purposes (abstract, expressionist, representational) for which the colors are used.
Is Every Color either Warm or Cool? The second question is whether every color should be described as either warm or cool, or only reds and yellows as opposed to greens and blues.
There are two conventions: one assigns an absolute quality to a color (this color is always warm) or a relative quality to a color (this color is warm in comparison with that color).
Most color theory texts categorize greens and purples as either warm or cool, because color theory likes things tidy. But I suggest that painters consider the hues from green yellow to green, and from violet blue to violet red, as fundamentally neither warm nor cool. In these hues, blue and red, or yellow and green, visibly mix they are warm/cool hybrids. The complementary contrast between green and violet also lacks the stridency of the contrast between red and green or yellow and violet blue. This yields the labeling scheme shown below.
warm vs. cool colors in the color circle
Whatever your views on this fundamental dichotomy, it's common practice and often useful to describe colors as relatively warmer or cooler in comparison with another color. This simply indicates whether the color is closer to red orange (warmer) or to green blue (cooler) than the comparison color or, closer to yellow or violet blue, if you prefer the alternative yellow/violet blue contrast. Thus, red is a warmer color than magenta, because red is closer to red orange; but both are warm colors in comparison to violet.
These relative comparisons are most often applied to analogous colors (of similar hue) a "warm blue" (compared to other blues) or a "cool red" (compared to other reds). Thus:
Occasionally a wider comparison is made across two or more hues, but it is still decided by the relative distance in a color wheel between the two colors and the warmest/coolest hue. Hooker's green is warm (closer to red orange or yellow) when compared with viridian, but is cool (closer to cyan or green blue) when compared with green gold.
It's always helpful to anchor the logic of this abstract color labeling in physical color mixing effects. Thus, the fact that hooker's green is warmer than viridian indicates that we can get a color equivalent to hooker's green by mixing viridian with an orange yellow or orange paint; the fact that it is cooler than green gold indicates that we can get hooker's green by mixing green gold with phthalo turquoise.
What about dull (near neutral) colors? If all colors must be either warm or cool, the common 19th century practice was to assign "gray" to the cool hues (as in a gray or overcast day). This is probably because most grays or dark neutral mixtures historically used in painting, including payne's gray, indigo and neutral tint, have been biased with a blue or green tint.
If colors are judged in relative terms, then a grayed color is either warm or cool using the same "distance in a color wheel" comparison as before. That is, a grayed blue green is warmer than a saturated blue green, because the gray is closer to red orange across the center of the hue circle. In paint mixing terms, some red orange has been mixed with the blue green in order to gray it, and this red orange appears as a warming of the color. (Again, it is always helpful to anchor the warm/cool labeling in co