Desktop looks very dim when I turn on HDR through windows settings. However only Win store games require to turn on hdr through W10 settings.
Other games switch to HDR automatically(you need select hdr through ingame menu, no more).
Nvidia color settings should be at auto, because when you launch HDR game, driver sets 422 10 bit automatically. When you return to SDR -driver sets 444 rgb automatically. Only one bad thing - rgb range is locked to limited. If you want full range -you need to set SDR settings manually.
980 ti+ks8500