CIE Colorimetry and Colour Displays

CIE colorimetry was standardised 65 years ago to describe colorimetric properties of signal lights. The first real application of CIE colorimetry occurred, however, in the textile and coating industries to describe colour matches between sample and reference. Thus also the experiments conducted to achieve a uniform colour scale diagram were performed by using material samples usually illuminated by a daylight simulator. Such experiments led to the recommendations for the CIELAB and CIELUV colour spaces. It has been a misinterpretation that CIELUV is more useful for self-luminous objects, derived from the fact that CIELUV has a chromaticity diagram and CIELAB has non. In recent years much effort has been invested to obtain a colour appearance model to be able to describe not only colour matches but also the appearance of colours, both as material samples and in order to be reproduced on colour displays. The three fundamental questions in this respect are: • Are the standard colour matching functions (cmf’s) representative of average human colour vision? • What is the proper description of chromatic adaptation? • What are the auspices of a CIE colour appearance model? A number of CIE Technical Committees are working on the different aspects of these questions. The paper presents a short review of the questions raised and, as far as feasible, will outline likely answers.