Colour perception in man is due to iodopsin pigment in cone cells. In the retina, there are three types of cones which respond to red (erythropsin), green (chloropsin) and blue light (cyanopsin). Other colours are detected by simultaneous stimulation of more than one type of cone cell.
Colour is defined first by frequency and then by how those frequencies are combined or mixed when they reach the eye.
- Light falls on specialized receptor cells called cones which is present at the back of the human eye called the retina and a signal is sent to the brain along a neural pathway which is referred to as the optic nerve.
- Cones are the nerve cells that are more sensitive to bright light. They help in detailed central and colour vision. This signal is processed by the part of the brain near the back of the skull named the occipital lobe.