Unfortunately, colorimetry’s famous CIE diagram cannot be used for determining colour differences as simple gradations on a chart. Indeed, this drawback, which is evident in the excessive representation of green and the bunching of red, violet and blue hues into the corners, has always been the subject of criticism. The CIEL*a*b* system is derived from the CIE Standard Colour Table by transforming the original X, Y and Z coordinates into the three new reference values of L, a and b. The objective of this transformation is a colour-space to aid the numerical classification of colour differences. (Detailed text)

Date: This uniform colour-space originated in 1976.

Country of origin: Commission Internationale d’Eclairage

Basic colours: The four basic psychological colours of red, green, blue and yellow

Form: Cube modified according to «psychometric colour diagram»

Application: Determination of colour difference

Related systems: HeringCIEACC

Bibliography: K. McLaren, «The development of the CIE 1976 (L*a*b*) uniform colour-space and colour-difference formula», Journal of the Society of Dyers and Colourists 92, pp. 338-341 (1976); G. A. Agoston, «Color Theory and Its Application in Art and Design», Heidelberg 1979.