Color Vision, Trichromacy theory

The human eye absorbs light from all wavelengths of the visible spectrum and perceives these as six colours broadly associated with particular wavelengths. Color such as does NOT exist, only in different wavelengths of light. Colour is an invention of the brain. There are three types of cone each possessing a different pigment which investigations have shown absorb light of different wavelengths. These are red, green, blue, cones which are most sensitive to red, green and blue light respectively. In laboratory tests it has been shown that all the different colours can be seen by using different combinations of pure red, green and blue light.

The most generally accepted theory of colour vision is the trichromacy theory, which states that different colours are produced by the degree of stimulation of each type of the colour sensation of white.