RGB
An additive, Trichromatic Color Model that is used to describe the mixing of colors of light sources (not pigments). Red Green and Blue are the Primary Colors and are added together in various ways to reproduce a broad array of colors.
The main purpose of the RGB color model is for the sensing, representation, and display of images in electronic systems, such as televisions and computers, but is based closely to human perception of colors.
RGB does not define the Chromaticities of the red/blue/green Primaries Colorimetrically, so mixed colors are always relative to the primaries (and thus definitions defined in RGB are device dependent). When the exact chromaticities of the red, green, and blue primaries are defined, the color model then becomes a Color Space (which are device independent), including:
Definitions of colors with the RGB model are usually given in Hex form, i.e. three 2-digit hexadecimal numbers (0-255), preceded by a hash (e.g. #e540a4 defining Schiaparelli Pink).