This Technical Report has been prepared by CIE Technical Committee 1-81 of Division 1 "Vision and Colour”. It reports on the performance of colour-difference formulae based on the results of experiments to evaluate colour differences visually. The report addresses small colour differences of adjacent colours. Visual responses are compared with calculated colour differences using five colour-difference formulae: CIELAB, CMC, LABJND, CIE94, and CIEDE2000. A power-function (PF) correction is also included. Using the STRESS index, the performances of the colour-difference formulae are tested without and with the PF correction.

In addition to the COM dataset used for the development of CIEDE2000, nine new datasets (with particular emphasis on colour differences below 2 CIELAB units) are included in this study. The datasets can be downloaded from the CIE server.

The publication is written in English, with a short summary in French and German. It consists of 31 pages with four figures and 12 tables and is readily available from the CIE Webshop or from the National Committees of the CIE.