This has been posted as an issue on Windows for years. I'm just adding that this is a bug found on the Mac version as well as late as 1.10.4. I'm attaching a recording of a document with a CYMK color profile. Dragging on any of the color pickers to the bottom does not select a pure black, even when the color panels show RGB colors. It is the CYMK document color profile that causes the issue.
The most problematic instance of this issue is with mask layers because the color panel defaults to show Grayscale colors. Dragging to get a "black" color does not actually select black. It's not obvious immediately, as it would be if the CYMK color sliders were shown.
This problem has apparently existed for years. Do we have any kind of plan for release for a fix for this?
I don't think this should affect any fix that may have been added, but just in case it does I'm on macOS Mojave 10.14.6.
Screen Recording 2021-11-16 at 5.12.46 PM.mov