What Is the Difference Between Warm and Cool Colors?

The distinction between warm and cool colors, not understood until the late 18th century, is based on perceived temperature. Those colors with a warm bias, evoke images of sun and fire, and generally include the hues red through yellow (plus browns and tans), while those with a cool bias are associated with an overcast day and include hues from blue-green through blue-violet (plus most grays). Blacks may have either a warm or cool bias.

Warm colors tend to advance into a composition and to stimulate and arouse viewers, while cool colors recede and tend to relax. Additionally, because objects in the distance are perceived to have a cool, bluish tint, juxtaposing warm and cool colors on a two-dimensional surface can help create the illusion of three-dimensional space. The perception of scale is also affected by color temperature: cooler objects appear smaller compared to those of equal scale with a warm bias.

Color mixing may shift the underlying bias of the combined color depending on the colors used. For example, primary yellow, a warm color, can be shifted to a cool lemon yellow by adding white, and primary blue, a cool color, can be shifted to a warm green with the addition of certain yellows.