USING A STANDARD GREY SCALE FOR COLOUR CHANGE IN A MULTI-ANGLE COLOUR-ASSESSMENT CABINET (PO14, Pages 287-294)

We performed 3 independent spectroradiometric measurements of the 9 colour pairs in the grey scale of the Society of Dyers and Colourist (SDC) at 6 different viewing angles, as provided by a byko-spectra multi-angle colour assessment cabinet. On the average, the CIELAB colour differences of these colour pairs showed a variability with viewing angle 4 times higher than the variability associated to the 3 independent measurements. BRDF measurements of the samples in the SDC grey scale confirmed their goniochromatism, which is not identical to the one shown by the samples in the grey scale of the American Association of Textiles Chemists and Colorists (AATCC). A pseudo-divergence bidimensional representation confirmed the results found for the two grey scales. We conclude that the viewing angle is a relevant parameter in the colour differences of colour pairs of commercial grey scales placed in multi-angle colour cabinets.