Color Perception
The physical world is supposed to be colorless. Man percept the light of certain wavelength of 350 to 750 nanometers. In the retina there are three types of color sensitive see cells, denoted cones. They are sensitive for three different wavelengths, short wavy, middle wavy and long wavy light. The cones collect the rays of their wavelength that incidents in the human eye, and direct them to the brain, where the real color perception evolves. We sense short wavy light as blue, middle wavy light as green and long wavy light as red.
The light that is composed of all three wavelengths with full intensity we percept white. If no electromagnetical waves of color spectrum incidents in our eye the perception of black evolves.