The processing of color begins with the activation of followed by the activation of

The processing of color begins with the activation of cells sensitive to one of the three colors red, green, or blue, followed by the activation of the opponent process cells. Humans have three cones which has photo-pigments that would be able to sense the different parts of the spectrum. Each of the cone would tune to their respective wavelengths. The long wavelengths corresponds to the color red, middle wavelengths is green and short wavelength for blue.

What are the answers

It is evolution, because we all have some of the same traits like eye color or shape or ears.