Rainbow colours are the bands of colour 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).
- The human eye, and so human perception, is tuned to the visible spectrum and so to spectral colours between red and violet. It is the sensitivity of the eye to this small part of the electromagnetic spectrum that results in the perception of colour.
- Defining rainbow colours is a question more closely related to the relationship between perception and language than to anything to do with physics or scientific accuracy.
- Even the commonplace colours associated with the rainbow 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 frequency it is our eyes and brains that interpret these and create our perceptions after a lot of processing.