Colour perception is subjective to the human eye. The eyes have specialised retinal cells for the definition of colour and wavelengths of light stimulates each of these receptor types to varying degrees and the brain combines the information from each type of receptor to allow perception of different perceptions of different wavelengths of light. The photopigments of the eye are encoded on the X chromosome (male) and defective encoding of these leads to the two most common forms of color blindness (which is most common in males as a colour blind mother will always pass on her genetic disorder to her son). A very small percentage of women may have an extra type of color receptor because they have different alleles for the gene each X chromosome. The inactivation of the X chromosome produces tetrachromatic colour vision, a disorder allowing the possessor four independent channels to convey colour information. The zebra fish for example has sensitivity to red, blue, green and ultraviolet light which can be utilised for the animal’s benefit. Insects also use their perception of two main wavelengths during pollination.
It is the ventral stream (purple) that controls the colour recognition as part of the visual cortex, but the body starts processing colour from the moment the retina accepts the light through initial colour component mechanisms.
Many theories of colour perception have been presented, in the 19th century by Thomas Young and Hermann von Helmholtz suggest that the retina’s three types of cones are sensitive to blue, green, and red. Ewald Hering proposed that the visual system interprets color in an antagonistic way: red vs. green, blue vs. yellow, black vs. white.