With V1960, Magenta Hue calculations are now incorrect. The attached two points have opposite hue rotations, yet both are shown with positive hue errors.

Attached file: Test.bcs

This is a misunderstanding on what the HSL bars widget represents.

It is an RGB to HSL conversion, based on the original RGB error.
If you research such conversion you can see the way it works.
(The original reported Red error was a real error.)

So this becomes a different question.
"Is the present operation the best approach for the HSL bars?"
We will think on that.

In the meantime, relevant info will be added to the User Guides.

Steve