NCS
A Swedish colour system that describes each colour by how it looks, in terms of six basic colours.
Also: Natural Colour System
The Natural Colour System was developed in Sweden and is a national standard there and in several other countries. It rests on the idea, put forward by the 19th-century German scientist Ewald Hering, that people experience six pure colours: white, black, yellow, red, blue and green. Any colour is described by its resemblance to these. A code such as S 2030-Y90R means twenty per cent blackness, thirty per cent colour strength, and a hue that is yellow with ninety per cent red. Architects and paint makers use it widely.