LIGHT

Rainbow

The rainbow is an arc of colours visible in the sky. Rainbows appear when the sunlight or the white light meets the millions of water droplets in the atmosphere. Then the light refraction will take place at the dividing line of air and water (this dividing line is termed as prism).  The light enters the droplets where it is split up into seven colours, unveiling the colours of the spectrum and said as the colours of the rainbow.

The link that follows will explain and illustrate how the seven colours of the spectrum refract… The Rainbow

Colour 

Colour is a light of different wavelenghts and frequencies separated in a spectrum or rainbow.

The retina located at the back of our eyeball contains cells highly responsive to light.  This layer at the back of our eye has three colour receptor cells that only distinguish colours red, blue and green.  The three colours then pass through the optic nerves to the brain where all the other colours are created or formed.