Final answer:
The trichromatic theory and the opponent-process theory are two theories of color vision that are complementary. The trichromatic theory explains color perception at the level of the retina, while the opponent-process theory describes visual processing in the brain. They work together to provide a comprehensive understanding of color vision.
Step-by-step explanation:
The two theories of color vision are the trichromatic theory and the opponent-process theory. The trichromatic theory suggests that there are three types of cones in the eye that are sensitive to different wavelengths of light, corresponding to the colors red, blue, and green. On the other hand, the opponent-process theory proposes that color is coded in opponent pairs, such as black-white, yellow-blue, and green-red. These theories are complementary rather than contradictory, as they apply to different levels of the nervous system. The trichromatic theory is more applicable to the retina, while the opponent-process theory describes visual processing beyond the retina in the brain.