Steps to reproduce:
1. Open new Unity project
2. Got to Preferences -> General window
3. Set the Editor Theme to Light
4. Go to Preferences -> Diagnostics window
5. Observe the "Warning!" icon
Expected result: The logo can be clearly seen in both Light and Dark Editor modes
Actual result: The logo is difficult to see in the Light Editor mode
Reproducible with: 2021.3.24f1, 2022.2.17f1, 2023.1.0b14, 2023.2.0a13
Could not test on: 2020.3.47f1 (Diagnostics window not available)