Color Constancy: The feature of the human color perception system which ensures that the perceived color of objects remains relatively constant under varying illumination conditions.
Trichromatic Theory:A theory of color vision stating that there are three types of photoreceptors in the retina, each sensitive to one of three primary colors: red, green, or blue.
Opponent Process Theory:A color vision theory that suggests colors are perceived through opposing pairs: red-green, blue-yellow, and black-white. This theory helps explain afterimages and certain aspects of color blindness.