Hesselgren’s observations do not only contribute to the future NCS system (NCS); they also assist in the development of colour-charts which are intended for use by architects and other professional groups involved in interior and exterior design. Start-point for the system is the observation that each impression of colour can arise through the perception of six elementary colours: namely, white, black, yellow, red, green and blue. The system, which is based on a 24-part full-colour-circle, attempts to bring increased substance and clarity to Johansson’s order system. (Detailed text)
In 1953, the Swede Sven Hesselgren published his Colour Atlas with the intention of giving tangible forms to Tryggve Johansson’s colour-solid. In Hesselgren’s Colour Atlas, 507 standard colours are specified, arranged in planes of equal hue according to brightness and saturation. The purpose of these colours is to provide the structure for a phenomenologically based system. Hesselgren’s observations do not only contribute to the future NCS system; they also assist in the development of colour charts which are intended for use by architects and other professional groups involved in interior and exterior design.
A 24-part full-colour-circle forms the basis of the Hesselgren atlas. Its full colours have been selected to contain the four basic colours — yellow, red, blue and green — attributable to Ewald Hering which, more that any other colours, are perceived as being psychologically independent. Accordingly, yellow appears neither reddish nor greenish, red neither yellowish nor blueish, blue neither reddish nor greenish and green neither blueish nor yellowish.
These four basic colours divide the circle into four quadrants, and these quadrants are in turn subdivided into gradations which are perceived as being equal. Five hues are placed between yellow and red, seven between red and blue, three between blue and green and three between green and yellow, so that initially 22 colours complete the circle. For practical reasons, a greenish blue and a greenish yellow hue are also inserted, in order to bring the total number to 24.
The order of colours conforms to hue, saturation and brightness. In addition, two further parameters — intensity or colour-strength, and clarity or veiling — are stipulated which, together with the three basic parameters, are viewed by Hesselgren as both necessary and sufficient to describe each colour in all its possible variations.
With Hesselgren, colours of the same saturation do not lie on the surface of cylinders arranged about an axis, but once again can be found on a series of concentric cones with black at their common tip, as shown to the right.
Date: This construction by phenomenologist Hesselgren is a preliminary step towards the production of a colour atlas and dates from 1953.
Country of origin: Sweden
Basic colours: Yellow, red, blue and green
Form: Modified double-cone
Application: Architecture, interior and exterior design
Related systems: Hering — Pope — Johansson — N.C.S.
Bibliography: S. Hesselgren, «Colour-Atlas», Stockholm 1955; S. Hesselgren, «Some basic facts about colour», Die Farbe 4, p. 304 (1955); S. Hesselgren, «Why Color Order Systems?», Color Research and Application 9, pp. 220-228 (1984).