Color wheels organize colors around three psychologically significant attributes:

Hue: Corresponding to the color's dominant wavelength. Hue varies as one travels around the wheel. It is our primary means of distinguishing colors.

Value: Corresponding to brightness. Value varies as one travels from the inside of the circle (high values) to the outside (low values). The white circle at the center of the wheel indicates whiter mixes of the colors on the wheel; the heavy black circle around the outside indicates progressively blacker mixtures.

Chroma: Corresponding to purity or saturation of color. To vary the chroma, a color may be mixed with varying amounts of the same value of gray. Lighting and, psychologically, adjacent colors, affect perceived saturations.

Most color wheels and color schemes differ from one another only in the choice of the primary colors: the colors from which all others are mixed. These differ when mixing light or mixing pigments.