Steps to reproduce:
1. Create new Unity project
2. Set Editor theme to Light (Preferences > General > Editor Theme)
3. Open Profiler (Window > Analysis > Profiler)
4. Observe the Profiler background behind the frame charts
Actual results: Dark background is missing behind frame charts
Expected results: Dark background is not missing behind frame charts
Reproducible with versions: 6000.5.0a5 (9b63d0bc55db), 6000.5.0a6
Not reproducible with versions: 6000.5.0a3, 6000.5.0a4 (35ed6e8537f8)
Tested on (OS): Ubuntu 24.04, macOS Silicon Tahoe 26.2 (M1)