This part of ISO 10545 describes a method for utilizing colour measuring instruments for quantifying the small colour differences between plain coloured glazed ceramic tiles, which are designed to be of uniform and consistent colour. It permits the specification of a maximum acceptable value which depends only on the closeness of match and not on the nature of the colour difference.
Colour variations produced for artistic purposes are not covered in this part of ISO 10545.
NOTE This test should only be used when small colour differences between plain coloured glazed tiles are important in a specification.