ColorAcademy 2005 - Natural Colour System

Natural Colour System
by Roy Osborne

The Swedish Natural Colour System (NCS) was introduced in 1979 by a team led by Dr Anders Hard.

In the NCS, colour sensations are plotted with reference to white, black, and the four unitary hues, yellow (Y), red (R), blue (B) and green (G), also known as the psychological primary colours.

The NCS colour solid, which forms the conceptual model for the system consists of a double-cone, with white located at the top and black at the base. The figure is bisected by a horizontal colour circle. Each quarter of the circle is subdivided into 10 regularly spaced hues.

Any colour sample within the system can be notated unambiguously by the three parameters, blackness (s, from the Swedish svart, meaning 'black'), whiteness (w), and chromaticness (c). So-called chromaticness identifies the degree of resemblence of a colour sample to one of maximum colour content located on the rim of the NCS hue circle.

An NCS colour notation can be thought of as indicating the location of a particular colour in relation to other colours within the system, as seen under specific conditions of illumination and viewing. With this in mind, the NCS notation 2050-Y70R, for instance, identifies a colour of 20% black content (located on a diagonal line), 50% colour content (or chromaticness, located on a vertical line) and of a 'yellowish-red' hue consisting of 70% unitary red and 30% unitary yellow. (Identifying the corresponding white content is unnecessary as it can be assessed by subtracting the black content plus the white content from 100.)

The NCS has attempted, with some success, in establishing a visual logic which enables the viewer to look at a surface-colour and mentally assess its location (and hence its notation) within the system as a whole. Though in theory the NCS Atlas is only an illustration of the system (and does not strictly identify the system itself), it offers a useful alternative to other published colour systems, such as those originally devised by Munsell and Ostwald.

Full details of the NCS publications can be obtained from the Scandinavian Colour Institute, PO Box 49022, S-100 28 Stockholm, Sweden (Telephone +46 8 617 47 00; Facsimile +46 8 617 47 47)

The NCS UK website at http://www.ncscolour.co.uk/ contains a number of useful resources including detailed information on the system, product information, services information and case studies.