DIN EN ISO 18314-4:2024-04

This document specifies a formalism for the calculation of the illuminant metamerism of solid surface colours. It cannot be applied to colours of effect coatings without metrical adaptation. This document only covers the phenomenon of metamerism for change of illuminant, which has the greatest meaning in practical application. In the case where chromaticity coordinates of a pair of samples under reference conditions do not exactly match, this document gives guidance on which correction measures to take. Regarding the reproduction of colours, the metamerism index is used as a measure of quality in order to specify tolerances for colour differences between a colour sample and a colour match under different illumination conditions. The quantification of the illuminant metamerism of pairs of samples is formally performed by a colour difference assessment, for which tolerances that are common for the evaluation of residual colour differences can be used. The responsible national standardization committee is Gemeinschaftsarbeitsausschuss NA 025-00-02 GA "Gemeinschaftsarbeitsausschuss FNF/FNL: Farbmetrik" ("Joint Working Committee FNF/FNL: Colometry") at DIN Standards Committee Colour (FNF).