Wow, very comprehensive explanation!
There are many good ideas in your post. This will be something I can work on in upcoming weeks after release.
Thank you !
Additional issues after using the program longer and logging them when found;
When using an Adjustment that uses Hue, it doesn't look back around in a circular manner. It should be enough to apply modulo to it like (hue+adj)%255 depending on how it's set up.
--- --- ---
RGB blending isn't in linearized gamma so Red to Green doesn't include the proper yellows and instead gives browns. However: Lots of people are used to RGB blending that isn't gamma corrected so it might be better to have the existing RGB Blending and underneath it Linearized RGB blending where it linearizes the gamma curve / tone curve of the assumed sRGB monitor and blends based on emitted light levels. It's much more painterly.
--- --- ---
The "WHEEL" color selector's Triangle or Square doesn't update in color when a new color is picked on the grid and it only updates when switching between Triangle and Square or HSV and HSL.
--- --- ---
It looks as though reds become magenta after using Luminosity and Chroma adjustments enough times, even though Hue is left alone.
--- --- ---
Setting the hue of a color on the grid with the HSL sliders, selecting another color to adjust the hue, and then going back to the past color shows that it's a different hue than what I left it with. It takes multiple edits to get a specific hue.
--- --- ---
LAB interpolation between light yellow and middle magenta results or resulted in cyan, which doesn't seem right.
--- --- ---
I could not get the LAB or RGB sliders in the left-most tab (if I remember the position correctly) to actually edit a selected color.
--- --- ---
Selecting colors from an image makes too many colors too fast. It seems to be based on the time of mouse 1 being held down because if I click on the image and don't move my mouse it'll make 6 or so duplicate colors. It should be based on moving over new pixels such that every new pixel that's moused over results in a new pixel or every new pixel with a limit like 10 per second or faster.
--- --- ---
This isn't very important if JzAzBz gets in since it's VERY close to the Munsell colors but there's a large set of colors called the Munsell Renotation Data (if I remember correctly) that were determined to have the same hue / chroma / luminosity and depending on where you get this data it should come with sRGB conversions, if not you should be able to convert to D65 sRGB from the XYZ / xyY coords it often comes with. These can be interpolated but the one time I saw a Munsell color picker with interpolated values it was extremely heavy processing. http://pteromys.melonisland.net/munsell/
--- --- ---
Something like Coolorus or Paletton or other online color theme / color scheme designers what let you divide a color wheel geometrically, otherwise a separate program has to be used to develop color schemes with guidance. This would be best with a Hue/Chroma transform of JzAzBz due to its very perceptually even arrangement of hues, whereas LAB has really stretched out blues and RGB's HSL/HSV has a lot of purple IIRC. The ability to link colors on the grid to draggable positions on the color scheme designer tool would be helpful so that linked blends and such can all update live when adjustments are made to the color scheme.
It looks like shaders are used for color conversion so here's a shader I wrote a while back for sRGB -> Jzazbz -> sRGB https://pastebin.com/DMBNjc6g Might save some time to take the guts of this rather than rewrite from the article.