Color discrimination as a function of saturation, field size, and adaptation level

The purpose of our research was to investigate color discrimination under conditions of ambient illumination that may reduce CRT display saturation and contrast. Our research measured both the variability of color matching and the offsets from a match necessary for a 100% discrimination difference. We did this for four dominant wavelengths each at five saturation levels. Our subjects were tested at low, medium, and high adaptation levels for both large and small test stimulus sizes. In general, our results for the low luminance color matching conditions are in agreement with the published literature. For the high luminance and small field conditions, our data suggest that color discrimination should not be predicted from the 1960 CIE Uniform Chromaticity Space data. Color discrimination varies dramatically with dominant wavelength; reds and greens are more difficult to discriminate than yellows and yellow-greens.