The site is named after the RGB colour system: an additive colour model in which the red, green, and blue primary colours of light are added together in various ways to reproduce the full spectrum of colour. The name of the model comes from the initials of the three additive primary colours: red, green, and blue.


RGB is a device-dependent colour model too, where differing electronic devices detect or reproduce a given RGB value differently from each other; this is where colour elements (such as phosphors or dyes) and their response to the individual red, green, and blue levels vary from manufacturer to manufacturer, or even in the same device over time. 

Typical RGB input devices could be image scanners, or digital cameras. Common RGB output devices might include TV sets and, more importantly, mobile phone displays of various technologies such as CRT, LCD, plasma, OLED, quantum dots, etc. Colour printers, on the other hand, are not RGB devices, but subtractive colour devices typically using the CMYK colour model.