Primary colours are sets of colours that can be combined to make a useful range of colours. The primary colours are those which cannot be created by mixing other colours in a given colour space. For subtractive combination of colours, as in mixing of pigments or dyes for printing, the primaries normally used are cyan, magenta, and yellow, though the set of red, yellow, blue is popular among artists. For additive combination of colours, as in overlapping projected lights or in CRT displays, the primary colours normally used are red, green, and blue.