The power of colour

“Human vision is trichromatic,” says Prof Andrew Stockman, a UCL colleague of Dr Lotto’s. “Like a colour television.” We have three different colour receptors, cones, in our eyes, each designed to pick up different wavelengths of light. These are red, green and blue. Most mammals, apart from a few of our fellow apes, have two, and so do most colour-blind people, meaning they can only detect green and blue wavelengths. If we had only one receptor, we’d see the world in something like black and white.

http://www.telegraph.co.uk/culture/art/10767459/Seeing-red-The-mind-bending-power-of-colour.html