The RGB System

Additive Colour Mixing

The RGB colour system consists of the following three primary colours: Red, green and blue. Their initials, R, G and B, were used for the colour system's name.

The RGB system is an additive colour model. Additive colours are used for television screens, beamers, slide projectors, displays, scanners, digital cameras, etc.

How the RGB system is set up:

The three primary colours, red, green and blue, form the x-, y- and z-axis of a Cartesian coordinate system. An RGB colour can be defined using 3 values, each between 0 and 255.

Thus, every axis can assume 256 values. If you multiply these, you will get 16.7 million colours (or combinations of colours). This is how many colours can be displayed by computer monitors by default.