[jacobolus]

> you can’t tweak any of the three parameters in either direction without going out of gamut

This is a good thing: it teaches you the shape of the gamut, and gets you working with colors consistently.

#FFFF0O does not have “plenty of practical value”. It is a very niche tool with an extremely small range of uses, and should be avoided almost all of the time.

> For colour pickers especially, perceptual colour spaces have just been no good,

Just the opposite: for color pickers especially, using anything else makes it much much harder to get good results.