An object's color depends on its ability to filter out the light of a particular wavelength. For example, a red apple's surface absorbs blue-green wavelengths and reflects the red one.

Colors with a dominating wavelength or hue are called chromatic. They include colors like red, orange, yellow, green, blue, indigo, and violet, as well as their shades and tints. Black, white, and gray are not chromatic, as they include an equal distribution of wavelengths.