We report preliminary results of an experiment measuring contrast sensitivity as a function of spatial frequency, location in color space and direction of variation. Observers viewed bipartite fields containing sinusoidal gratings on one side and a uniform field on the other, having the same mean color. The experiment used a forced choice paradigm to measure thresholds for a large number of observers and a large number of mean color/spatial frequency/direction of variation combinations, although no one observer saw every combination. While early data is noisy, we have found contrast sensitivity as a function of spatial frequency, on average, when any of L*, a*, b*, C* or Hab is varied. We have not yet found any meaningful dependency on any independent variable other than spatial frequency, such as C*, as would be expected from such color difference metrics as CIE ΔE94 or ΔECMC.
R. Victor Klassen, Nancy Goodman, "Human Chromatic Contrast Sensitivity: Exploration of Dependence on Mean Color" in Proc. IS&T 8th Color and Imaging Conf., 2000, pp 31 - 38, https://doi.org/10.2352/CIC.2000.8.1.art00007