This document specifies the procedure and test report for determining small colour differences of object colours according to equidistant colour spaces. Three suggestions for metrics for the quantitative determination of small colour differences (？E？<？5) of non-luminous colours are given in Annexes？A, B and？C. These examples are related to the three colour space models: OSA-UCS modified by Oleari et al., DIN99o and CAM16-UCS (uniform colour space).

This document is applicable for the assessment of pigments, dyestuff and extenders in the field of coatings, plastic and prints only that are evaluated in pairs for colour conformity, and which have small perceptible colour differences.