Natural Color System

The research team consisted of Anders Hård, Lars Sivik and Gunnar Tonnquist, who in 1997 received the AIC Judd award for their work.

E.g. a saturated pink would be fully defined by its visual similarity to red, blue, black and white.

with In addition to the above values s (blackness), w (whiteness), c (chromaticness) and Φ (hue), the NCS system can also describe the two perceptual quantities saturation and lightness.

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 markets.

[5] The underlying physiological mechanisms involved in color opponency include the bipolar and ganglion cells in the retina, which process the signal originated by the retinal cones before it is sent to the brain.

Models like RGB are based on what happens at the lower, retinal cone level, and thus are fitted for presenting self-illuminated, dynamic images as done by TV sets and computer displays; see additive color.

More problematic is the relation with the CMYK-model which is generally seen as a correct prediction of the behavior of mixing pigments, as a system of subtractive color.

Observing that the mix of yellow and cyan paint results in a green color, would thus be at odds with the intuition of pure human perception which would be unable to account for such a "yellowblue".

Colorimetrist Jan Koenderink, in a critique of Hering's system, considered it inconsistent not to apply the same argument to the other two subtractive primaries, cyan and magenta, and see them as unique hues as well, not a "greenblue" or a "redblue".

He also pointed out the difficulty within a four color theory that the primaries would not be equally spaced in the color circle; and the problem that Hering does not account for the fact that cyan and magenta are brighter than green, blue and red, whereas this is, in his view, elegantly explained within the CMYK-model.

However, note that these codes are only approximate, as the definition of NCS elementaries is based on perception and not production of color.