A set of colors is harmonious when their mixture yields a neutral gray

Itten defines color harmony physiologically: the eye and brain seek equilibrium, which corresponds to neutral gray (Hering’s psychophysiological zero point). Therefore two or more colors are harmonious if — and only if — their mixture produces a neutral gray. This requires that the three primary colors yellow, red, and blue be present in suitable proportions. Any complementary pair automatically satisfies this because each complementary contains the two primaries not in the other. Color combinations whose mixture does not yield gray are ‘expressive’ or discordant — they create tension rather than equilibrium. This is an objective criterion that replaces subjective taste judgments about ‘pleasant’ color combinations.

Examples

Yellow + violet = gray (because violet = red + blue); orange + blue = gray; red + green = gray. A palette of yellow, red, blue in correct proportions is harmonious; a palette skewed toward red-orange is expressive, not harmonious.

Assessment

Given three color swatches, predict whether their mixture is neutral; explain why a complementary pair is always harmonious by this rule; contrast Ostwald’s ‘harmony = order’ definition with Itten’s physiological definition.