How Do We See In Color?

Cones, the photoreceptor cells in the retina responsible for color vision, recognize either red, green or blue (these primary colors correspond to distinct wavelengths of light). When combinations of these colors appear together, say in the case of yellow light, where red and green are both present, the cones corresponding to individual wavelengths are activated simultaneously. Your brain recognizes this as yellow.

Video by TED-Ed via It’s Okay To Be Smart.