videos are forced to play with hdr after 0.41.0 release

mpv Information

mpv v0.41.0 Copyright © 2000-2025 mpv/MPlayer/mplayer2 projects
 built on Dec 28 2025 12:02:53
libplacebo version: v7.351.0
FFmpeg version: n8.0.1
FFmpeg library versions:
   libavcodec      62.11.100
   libavdevice     62.1.100
   libavfilter     11.4.100
   libavformat     62.3.100
   libavutil       60.8.100
   libswresample   6.1.100
   libswscale      9.1.100

Other Information

- Linux version: CachyOS x86_64
- Kernel Version: Linux 6.18.2-3-cachyos
- GPU Model: AMD Radeon RX 9070 XT
- Mesa/GPU Driver Version: Mesa 25.3.2; 
- Window Manager and Version: hyprland 0.53.0
- Source of mpv: cachyos/AUR
- Latest known working version: 0.40.0
- Issue started after the following happened: updated to 0.41.0

Reproduction Steps

mpv 9634885db72904a62442f3f658297875.mp4 --log-file=output.txt --no-config

Tried rebuilding from master, but still same problem.

Expected Behavior

Video plays with usual colors

Actual Behavior

Video plays with too bright colors, noticable black screen when forcing fullscreen mode, which looks similar to forced HDR mode

Log File

0.40.0 (Correctly working version) log:

output_old.txt

0.41.0 (broken) log:

output.txt

Sample Files

No response

I carefully read all instruction and confirm that I did the following:

• I tested with the latest mpv version to validate that the issue is not already fixed.
• I provided all required information including system and mpv version.
• I produced the log file with the exact same set of files, parameters, and conditions used in "Reproduction Steps", with the addition of --log-file=output.txt.
• I produced the log file while the behaviors described in "Actual Behavior" were actively observed.
• I attached the full, untruncated log file.
• I attached the backtrace in the case of a crash.

Start by comparing the attached output_old.txt and output.txt logs for the same mpv command, using the reported 0.40.0 and 0.41.0 versions and the no-config reproduction. Trace the display or HDR behavior involved with fullscreen playback on Linux; done means the video retains its usual colors without forced HDR-like output.