rods
26.3 Color and Color Vision The eye has four types of light receptorsrods and three types of color-sensitive cones. The rods are good for night vision, peripheral vision, and motion changes, while the cones are responsible for central vision and color. We perceive many hues, from light having mixtures of wavelengths. A simplified theory of color vision states that there are three primary colors, which correspond to the three types of cones, and that various combinations of the primary colors produce all the hues. The true color of an object is related to its relative absorption of various wavelengths of light. The color of a light source is related to the wavelengths it produces. Color constancy is the ability of the eye-brain system to discern the true color of an object illuminated by various light sources. The retinex theory of color vision explains color constancy by postulating the existence of three retinexes or image systems, associated with the three types of cones that are compared to obtain sophisticated information.