How the System works

History | How the System works | Licensed SA Companies

The Natural Colour System (NCS) is a logical colour system that builds on how people see colour. The system allows all imaginable surface colours to be described and given unambiguous NCS notations.

The six elementary colours


The six pure colours that are the basis of the built-in ability of humans to characterise different colours are white W, black S, yellow Y, red R, blue B and green G –the six elementary colours.
NCS colour notations are based on how much a given colour seems to resemble these six elementary colours.

NCS colour notation


In the NCS designation 1050-Y90R, for example, 1050 indicates the nuance, or the degree of resemblance to black S and to the maximum hue C; in this case, 10% blackness (s) and 50%
chromaticness (c). The hue Y90R indicates the percentage resemblance of the colour to two chromatic elementary colours, here Y and R. Y90R means yellow with 90% redness.
Purely grey colours lack colour hue and are given only nuance notations followed by -N as neutral. White is written as 0300-N and is followed by 0500-N 1000-N, 1500-N, and so on to 9000-N, which is black. The letter S preceding the complete NCS notation (S 1050-Y90R) means that this is a standardised NCS sample from NCS Edition 2.

NCS Colour Space


In this three-dimensional model, called the NCS Colour Space, all imaginable surface colours can be placed and thus be given an exact NCS notation. To understand more easily the parts included in the NCS notation, the double cone is divided into two two-dimensional models, the NCS Colour Circle and the NCS Colour Triangle.

NCS Colour Circle


The NCS Colour Circle is a horizontal section through the middle of the colour space where the four chromatic elementary colours are placed like the points of a compass. Each quadrant between two elementary colours has been divided into 100 equal steps. In the figure, the hue Y90R, yellow with 90% redness, has been marked.

NCS Colour Triangle


The NCS Colour Triangle is a vertical section through the colour space. The base of the triangle is the grey scale from white (W) to black (S) and the apex of the triangle is the maximum chromaticness (C) in the current hue, here Y90R.Colours of the same hue can have different blackness or chromaticness values, that is different nuances. This can be illustrated in colour triangles, where the scales are divided into 100 steps. In the figure, the nuance 1050 has been marked, a colour with 10% blackness and 50% chromaticness.