DS/EN ISO 105-A05:1998 Textiles - Tests for colour fastness - Part A05: Instrumental assessment of change in colour for determination of grey scale rating
The standard specifies an instrumental method for assessing the change in colour of a test specimen in comparison to an identical untreated reference, and the calculations undertaken to convert the instrumental measurements into a grey scale rating. This method is intended as an alternative to the methods for visual evaluation of the effect of a colour fastness test on any textile material.