All primary colours as well as those produced by adding the primary colours in suitable proportions are characterised by three main features: hue, brightness and saturation.
Hue : The colour itself is called the hue and depends on the dominant wavelength of the light. By adding two or more of the primary colours many hues are produced.
Brightness : Each colour produces a certain amount of brightness. Brightness of a colour is determined by the amount of light energy contained in it. Light energy is measured in lumens.
Saturation : The amount of white light contained in a colour determines its saturation level. For instance, a highly saturated or deep red light will contain a much less amount of white light than a dull red ...