Current state of things:
"Hue" is the normal, boring, RGB hue that's mostly green.
"Fair hue" is a scale of fully saturated colors (except for brown, of course, but even those are about 90% saturated, which is why they're pale-ish browns) but with 1/8 of the scale for each of red, brown, orange, yellow, green, cyan, blue, purple.
It turns out that the set of useful colors (at least to my taste) have lots more shades (darker than fully saturated) than tints (lighter), so "color" is a scale that's meant to be usable as a single color number, ignoring the three-dimensional nature of the full color space, that includes greyscale, divides the rest of the scale fairly among hues, and varies continuously between roughly 50% and 100% saturation in each hue range. It's "roughly" 50% because the darkest shades are mostly colors with names, e.g., maroon, navy, etc. And brown and orange are the same hue range, so a dark orange is brighter than a light brown, more or less.
Finally, "crayon" is the set of 100 named colors, mostly but not entirely X11 colors, from the existing crayon library, with no attempt at continuity.
Still to be done: In the color scale, saturation is continuous but not differentiable. I should try a sinusoidal interpolation to see if that looks better.