A chroma scaling psychophysics experiment was conducted using a CRT in a dark surround. The experiment consisted of constant hue and lightness IPT step ramps on a uniform background. Each hue step ramp was displayed on an achromatic, a medium and a high chroma background. The results clearly show that chroma scaling is dependent on the chroma of the background. For the medium chroma backgrounds a modest crispening effect is evident. The results also show that chroma scaling on achromatic and high chroma backgrounds differ considerably. The data for the achromatic backgrounds are used to compare C*, C and CF chroma metrics. Additional comparisons using several of the phases of the LUTCHI data demonstrate that C and CF are clearly better than C* and that C has an intercept of roughly 0.1 for a linear fit between normalized scale and metric data. In comparison, CF provides a good fit to the chroma scaling data and an intercept closer to 0.
Nathan Moroney, "Chroma Scaling and Crispening" in Proc. IS&T 9th Color and Imaging Conf., 2001, pp 97 - 101, https://doi.org/10.2352/CIC.2001.9.1.art00018