Figure 1.

Samples for measuring typical and unique red (a) and yellow (b). In each sample (row), hue varies at constant lightness from left to right. The vertical white and black lines within each sample indicate the location of typical red (a) and yellow (b) and the boundary between yellow and green (b) according to Olkkonen et al. (2010). In panel (a), the upper row shows the “blue-biased” Sample 1. In that sample, saturation (i.e., Munsell chroma) is higher for the five Munsell chips to the left bluish than for the five chips towards the right yellowish hue direction. Sample 2 in the lower row is yellow-biased with higher saturation to the right yellowish hue direction than to the left. In panel (b), Sample 1 is red-biased and Sample 2 green-biased for the measurement of typical and unique yellow. They are green-biased (Sample 1) and yellow-biased (Sample 2) for the measurement of binary yellow–green because the saturation–hue relationship reverses at the binary hue (black line).