Well, by the way, the documentation says that the circle uses OKHSL.
"Color wheel
LMB to pick a color from the wheel. Click or drag in the hue ring around the color wheel to change only the hue. The hue ring uses OkHSL for better perceptual uniformity when changing hues."
Here's an interesting thing. In the color editor, there is a blend tab that shows a beautiful gradient based on OKHSL rules. However, monotorgb will give us a different, more washed-out/grayish gradient based on RGB rules. It's a bit of a shame. Of course, I made a manual OKHSL ramp for myself a long time ago, but native nodes are always better.I understand that with the abundance of color spaces and the focus on ACES, you can't just easily throw an OKHSL option into the ramp. Still, adding a selection dropdown at the user's own risk would be nice, don't you think?