Determination of unique hues using munsell color chips

Forty observers determined their unique hues from arrays of Munsell chips i n a standard surround under artificial daylight. There was some discrepancy in the results of males and females. Essentially no variability due to age of observed was found. The standard deviation around the total mean was le ss than I Munsell 40 hue step. Simple linear opponent-color a and b values were calculated The ranges were found to straddle in all bur the red color the system axes for the CIE 2 degrees observer, but not for the 10 degrees observer NCS unique hues determined at similar chroma and lightness values fell in all cases within the ranges. The shifts in cross-over wavelengths o f the color-matching functions necessary to match the extreme range values were determined to be between 6-11 nm. The results provide support for an o pponent-color system based on subtractions of color-matching functions. The y also point to significant variation ill color normal observers. (C) 2001 John Wiley & Sons, Inc.