Rainbow colours

Rainbow colours are the colours seen in rainbows and in other situations where visible light separates into its component wavelengths and the spectral colours corresponding with each wavelength become visible to the human eye.

  • The rainbow colours (ROYGBV) in order of wavelength are red (longest wavelength), orange, yellow, green, blue and violet (shortest wavelength).
  •  It is the sensitivity of the human eye to this small part of the electromagnetic spectrum that results in our perception of colour.
  • Naming rainbow colours is a matter more closely related to the relationship between perception and language than anything to do with physics or scientific accuracy.
  • Even the commonplace colours associated with rainbows defy easy definition. They are concepts we generally agree on, but are not strictly defined by anything in the nature of light itself.
  • Whilst the visible spectrum and spectral colour are both determined by wavelength and/or frequency it is our eyes and brains that interpret these differences in electromagnetic radiation that result in our colour perceptions.
  • In the past, rainbows were sometimes portrayed as having seven colours: red, orange, yellow, green, blue, indigo and violet.
  • Modern portrayals of rainbows reduce the number of colours to six spectral colours, ROYGBV.
  • In reality, the colours of a rainbow actually form a continuous spectrum and there are no clear boundaries between one colour and the next.