Pair comparisons were used to assess the perceptual uniformity of the Munsell value (V) and chroma (C) scales near 5Y 7.5/1 for both small (0.25–0.75) and larger (1–2) increments in V and C. We conclude that in this region perceptual linearity is retained down to steps of 0.25 V or C. Bisection experiments showed that around IOR 7/8 perceptual linearity in Munsell hue (H), V, and C was retained down to step sizes of 0.25 H, 0.10 V, and 0.25 C.
Robert T. Marcus and Fred W. Billmeyer, Jr., "Step size in the Munsell color-order system by pair comparisons near 5 Y 7.5/1 and bisections near 10R 7/8," J. Opt. Soc. Am. 65, 208-212 (1975)