Natural Color System (NCS)
The Natural Color System (NCS) is a proprietary perceptual color model
published by the Scandinavian Colour Institute (Skandinaviska Färginstitutet
AB) of Stockholm, Sweden. It is based on the color opponency description of
color vision. The system is
usually used for matching colors (using printed reference cards), rather than
The NCS is based on the six elementary color percepts of human vision - the
psychological primaries - as described by color opponency - white, black, red,
yellow, green, and blue - which are difficult to define
perceptually in terms of others. All the other perceptual colors are composite
perceptions that can be defined in terms of those six
(for example, turquoise looks like "blue green", orange like "a color that is
both reddish and yellowish," and brown looks like "a very dark orange," that
is, like a mixture of red, yellow and black). This all means the appearance of
a color can be readily predicted from its NCS notation, whereas its notation in
systems such as RGB often looks unintuitive (for example, yellow does
not look like "a reddish-greenish color" at all, even though the yellow on an
RGB monitor is obtained by mixing red and green lights).
Colors in the NCS are defined by three values, specifying the amount of
blackness (darkness), chromaticity (saturation), and a
percentage value between two of the colors red, yellow, green or blue (hue).
The blackness and the chromaticity together add up to less than or equal to
100% - their remainder from 100%, if any, gives the amount of whiteness. The
complete NCS color notations can also be tagged with a letter giving the
version of the NCS color standard that was used to specify the color.
The NCS is represented in 19 countries and is the reference norm for color
designation in Sweden (since 1979), Norway (since 1984) and Spain (since 1994).
It is also one of the standards used by the International Colour Authority, a
leading publisher of color trend forecasts for the interior design and textile