  =     =

This is the most often met colorimetric space, used in particular for television and computer screens, of so-called ‘additive synthesis’ (as opposed to the ‘subtractive synthesis’ while using white light and subtracting from it a part of the spectra by filters, which is for example the case in printing, where each ink acts like a filter on the white paper). Its definition rests on the choice of three primary colours: the red, the green and the blue.