Additive colour is colour created by mixing light of two or more different colours. Red, green and blue are the additive primary colours normally used in additive colour system. Additive colour is in contrast to subtractive colours in which colours are created by subtracting (absorbing) parts of the spectrum of light present in ordinary white light, by means of coloured pigment, or dyes, such as those in paints, inks, and the three dye layers in typical colour photographs on film. A subtractive colour model explains the mixing of a limited set of dyes inks paint pigments or natural colorants to create a wider range of colours each the result of partially or completely subtracting (that is, absorbing) some wavelengths of light and not others. The colour that a surface displays depends on which parts of the visible spectrum are not absorbed and therefore remain visible.