STALKER 2 (and other UE5 titles as observed by others ) seems to incorrectly display HDR, despite it working in other titles.

Considering how the screenshots I've taken with KDE's Spectacle tool look 1:1 how they do in-game I think something isn't being set correctly. I don't have a windows rig to test it out there, but I assume it works correctly. Let me know if this turns out to not be a vkd3d-proton issue, I'm happy to forward this bug report along to wherever is correct.

Also please excuse the 4k 4:3 screenshots lol, this also occurs at 3840x2160.

Software information

S.T.A.L.K.E.R. 2: Heart of Chornobyl (v2.0.3)

System information

• GPU: RX 7900 XT
• Driver: Mesa / radv 26.2.1
• Wine version: Valve Wine commit 36078f5f947532885a596dabbc7893c048133660 bundled with proton-ge 11-5
• VKD3D-Proton version: Commit 731c4aae5991b33f2ddab45d3cb1b4779159bf4b bundled with proton-ge 11-5

Additionally:

• EndeavourOS / Arch
• KDE Plasma: 6.7.4
• Kernel: 7.1.9-arch1-2
• Wayland

I've enabled HDR in KDE plasma, and have calibrated it to my monitor MPG 274URDFW E16M (Firmware FW.026).

Proton-GE 11-5-x86_64 with the following command line: PROTON_LOG=1 PROTON_ENABLE_HDR=1 PROTON_ENABLE_WAYLAND=1 %command%.

I've observed this under proton-cachyos-11.0-20260703-slr-x86_64 and a gamescope session (outside of plasma) with the correct cli params.

I've also attempted this on a Bazzite KDE - RX 9060 XT and a LG C4 living room setup (with hdr enabled), and I get the same results.

Log files

steam-1643320.log

Screenshots

Lamp flame (hdr)

Notice the purple in the flame. This is with HDR brightness set to 100% in-game to help demonstrate the issue.

Lamp flame (srgb / sdr)

Flame appears as normal in this screenshot

Outside distant trees (hdr)

Notice the purple in the distant tree.