yes, agreed 100%. I think that the official OCIO answer on the “color_picking” role would be : “we removed it from the next ACES OCIO Configs because its behavior is too different between softwares.” Which in my opinion was not necessarily the right move.
I would have preferred that we settle on defining it precisely and making sure that all developers are on the same page. This is the current definition :
colors in a color-selection UI can be displayed in this space, while selecting colors in a different working space (e.g.
scene_linearortexture_paint).
The ambiguous word here is “displayed”. I asked in one of the OCIO meetings to replace it by “set” or “defined”. But instead, they updated the docs with this warning :
Unfortunately there is a fair amount of variation in how applications interpret OCIO roles. This section should be expanded to try and clarify the intended usage.
So I guess it is up to the Blender users/devs to implement it the way they prefer. If I can give you any advice, here is the link for developers for MixingHelpers in C++.
And here is the mockup I did and presented at a couple of OCIO meetings some months ago :
I thought it would help clarifying some concepts about Color UI (not specifically in Blender but more for softwares in general).
Chris