A description is given of the Chromatic Adaptation Transform, CMCCAT97
, used in the recently adopted colour appearance model, CIECAM97s, and
the transform is used to derive a Colour Inconstancy Index, CMCCON97,
for changes caused by the use of illuminants of different chromaticit
ies. A worked example is included. (C) 1998 John Wiley & Sons, Inc.