Rainbows and bands of colour

About rainbows and bands of colour
  • There seem to be a number of reasons that an observer looking at phenomena such as rainbows  sees bands of colour:
    • The human perceptual system prioritise the simplification of colour information rather than observing a gentle gradient across the spectrum.
    • Our eyes respond to colours in terms of their relative brightness as well as their hue when presented with a section or the whole of the visible spectrum.
    • Observers look for colours they know and recognise.
    • Cone cells in our eyes are particularly sensitive to red, green and blue wavelengths because of the trichromatic nature (trichromacy) of human vision.