trichromatic theory

n. A conceptualization of the process of human color perception which suggests that all perceived hues are combinations of three basic hues, blue, green, and red, for which there must be specific sensory receptors whose combined activity gives rise to all perceptions of hue. This theory has largely been supported by modern physiology and expanded by the idea of opponent processes among the different visual receptors. Also called the Young-Helmholtz theory.