Additive colour

Additive colour is a method of mixing different wavelengths of light to produce other colours.

  • An additive approach to colour is used in the case of emission of light from the screens of mobile phones, computers and televisions.
  • An additive approach to colour is used in the case of the reflection of light off-white, neutral or black surfaces by digital projectors.
  • RGB colour is an additive colour model that combines wavelengths of light corresponding with red, green and blue primary colours to produce other colours.
  • Red, green and blue are called additive primary colours in an RGB colour model because they can be added together to produce all other colours.
  • RGB colour uses three light sources or beams. Each is called a component of the resulting colour,
  • Different colours are produced by varying the intensity of the component colours between fully off and fully on.
  • When fully saturated red, green and blue primary colours are combined they produce white.
  • When any two fully saturated additive primaries are combined they produce a secondary colour: yellow, cyan and magenta.
  • Some RGB colour models can produce over 16 million colours by varying the proportion and intensity of each of the three primary colours.