Plasma 6 has officially been released, with it comes partial HDR support:
Plasma on Wayland now has partial support for High Dynamic Range (HDR). On supported monitors and software, this will provide you with richer and deeper colors for your games, videos, and visual creations.
Set an ICC profile for each screen individually and Plasma will adjust the colors accordingly. Applications are still limited to the sRGB color space, but we are working on increasing the number of supported color spaces soon.
To improve Plasma’s accessibility, we added support for color blindness correction filters. This helps with protanopia, deuteranopia or tritanopia.
I will be exploring it with AOC Q27G3XMN. I hope this thread can be a good place to discuss HDR on Linux and maybe make a difference in it’s progress.