From ArchWiki

This page will serve as a guide to the current state of HDR monitor support on Linux.

HDR video support

HDR support on Linux is not implemented yet in the display servers, though it is being worked on:

HDR gaming support

The recently launched DXVK v2.1 includes HDR support however there are still a few caveats:

  1. HDR is currently only supported on AMDGPU.
  2. A Gamescope session is required and must be using the --hdr-enabled flag.
  3. You must set either DXVK_HDR=1 as a global environment variable or dxgi.enableHDR = True in the per app DXVK configuration file.