What are the two theories of color vision called?

The two main theories of color vision are the Trichromatic Theory and the Opponent-Process Theory. The Trichromatic Theory, proposed by Thomas Young and Hermann von Helmholtz, suggests that the human eye has three types of color receptors sensitive to red, green, and blue light. In contrast, the Opponent-Process Theory, developed by Ewald Hering, posits that color perception is controlled by opposing pairs of colors: red-green, blue-yellow, and black-white. Together, these theories provide a comprehensive understanding of how we perceive color.