Talk:XO colors

How were these colors arrived at? I'm curious because there are some that are very close together (EG, BCCEFF and BCCDFF). When you look at just the luminance (for evaluating distinguishability for colorblind people or on a b/w screen), there is even more clustering, with most adjacent colors (ordered by luminance) differing by <2%.

Evenly spacing 20 colors along the luminance spectrum would provide a set of much more distinguishable colors (5% difference in luminance between adjacent colors). Using a 8/21 rotation around the hues (all with 100% saturation) can give fairly distinguishable colors. That could be further improved by either varying saturation, increasing the hue rotation at the extremes of luminance (and decreasing toward the middle), or any of a number of other means.