The visible spectrum

White light from the Sun and light bulbs consists of light of all the colours in the visible light spectrum (a rainbow). A transparent triangular prism can split up sunlight into a visible light spectrum. The visible light spectrum shows the range of colours that light can have. Cone cells in the eye detect colour. There are 3 kinds (R, G and B); each is sensitive to a range of colours of light. The colour we see depends on which cone cells are triggered to send a signal to the brain.