Secondary colour

A secondary colour is a colour made by mixing two primary colours in a given colour space. The colour space may be produced by an additive colour model that involves mixing different wavelengths of light or by a subtractive colour model that involves mixing pigments or dyes.

  • Secondary colours produced by an additive colour model are quite different from the spectral colours seen in a rainbow.
  • A spectral colour is produced by a single wavelength, or a narrow band of wavelengths, within the visible spectrum.
  • A secondary colour produced by an additive colour model results from superimposing wavelengths of light from different areas of the visible spectrum.
  • For the human eye, the best additive primary colours of light are red, green, and blue.
  • RGB colour can be used to produce an extremely wide range of colour.
  • Because RGB colour involves adding different wavelengths of light together (thus the term “additive colour”), the resulting combinations always appear lighter to an observer.
  • When all three primaries (or for that matter all three secondaries) are combined in equal amounts, the result is white.
  • The RGB secondary colours produced by the addition of light turn out to be the best primary colours for pigments, the mixing of which subtracts light.