Several sets of data on visual sensitivity to color differences are now available. All of these data, however, have been obtained using optical arrangements differing from those employed in practical color matching. Data on visual sensitivity to color differences on textiles under ordinary viewing conditions have been obtained in this study to check the validity of the previous data for practical use.
Observations were made by four professional colorists on a red, a blue, and a green series of wool dyeings. Each series contained about twenty samples, and each sample was judged independently against a standard three times by each observer. Since dyers’ terminology was used, a means of conversion to I.C.I. notation had to be developed.
The MacAdam ellipses are found to be a good representation of visual sensitivity to chromaticity differences under common viewing conditions, providing these ellipses are taken to represent a difference somewhat larger than a least perceptible difference rather than the ⅓ L.P.D. reported by MacAdam. Visual sensitivity to differences in apparent luminous reflectance is found to be about 0.1 Munsell value steps, or considerably poorer than that which has previously been reported.
H. R. DAVIDSON, "Visual Sensitivity to Surface Color Differences," J. Opt. Soc. Am. 41, 104-110 (1951)