Door Kickers 2 saturation/brightness issues for proton versions after 9

Issue transferred from https://github.com/ValveSoftware/Proton/issues/9898.
@Orum posted on 2026-06-22T20:17:55:

Compatibility Report

• Name of the game with compatibility issues: Door Kickers 2: Task Force North
• Steam AppID of the game: 1239080

System Information

• GPU: 4080 Super
• Video driver version: Nvidia 595.71.05
• Kernel version: 6.18.26
• Link to full system information report as Gist: link
• Proton version: Varies; last working version is proton 9, versions 10 and 11 both have issues.

I confirm:

• [x] that I haven't found an existing compatibility report for this game.
• [x] that I have checked whether there are updates for my system available.
  compressed proton log file

Symptoms

When starting this game with the current Proton 10 or 11, the screen is darker and much more saturated than it should be. This is immediately obvious even on the main menu screen, but even more severely impacts gameplay. In some cases, I can't even see the map at all because things are so dark. It seems a little worse with Proton 10 than 11, but both are quite bad. With proton 9 there are no issues, so this appears to be a regression of some kind.

Reproduction

Start the game with either proton 10 or 11 and look at the main menu or any gameplay scenario. Compare it with proton 9 to see what things should look like.