Steps to reproduce:
1. Create new Unity project
2. Switch Editor theme to Light (Settings > General > Editor Theme > Light)
3. Install Asset Manager package via Package Manager
4. In project import provided “PNG_file.png”, “Dragon 2.5_fbx” files
5. Right-click on imported Assets and select “Upload to Asset Manager”
6. Open Asset Manager Window (Window > Asset Manager)
7. Upload the Asset to the Asset Manager window
8. Switch between “Assets” and “In Project” tabs
9. Observe the loading icon in the middle of the Assets preview images 

Actual results: Loading icons are barely visible on the Asset Preview images when switching tabs in Asset Manager window in Light Editor Theme
Expected results: Loading icons are visible on the Asset Preview images when switching tabs in Asset Manager window in Light Editor Theme

Reproducible with versions: 1.7.0 (6000.0.58f1, 6000.2.6f1, 6000.3.0b3, 6000.4.0a1)

Tested on (OS): macOS Silicon, Tahoe 26.0 (M1)