ADOPTED_FROM:EN ISO 11664-6:2016 ISO 11664-6:2014 specifies the method of calculating colour differences according to the CIEDE2000 formula. ISO 11664-6:2014 is applicable to input values of CIELAB L*, a*, b* coordinates calculated according to ISO 11664-4:2008(E). ISO 11664-6:2014 may be used for the specification of the colour difference between two colour stimuli perceived as belonging to reflecting or transmitting objects. This includes displays, if they are being used to simulate reflecting or transmitting objects and if the tristimulus values representing the stimuli are appropriately normalized. ISO 11664-6:2014 does not apply to colour stimuli perceived as belonging to areas that appear to be emitting light as primary light sources, or that appear to be specularly reflecting such light.