Definitions for "Primary Colour"
Three (or more) ground colours of a display which build all the other colours. Generally, red, green, and blue are used as primary colours of a projection system.
One of a small set of coloured lights which, when added together in different proportions, can produce a wide range of perceivable colours.
A colour that cannot be produced by mixing any combination of other colours. The three primary colours of light are red, green and blue.