Reproduction steps:
1. Create a new project and make sure Editor is in dark theme
2. Open Animation window (Window > Animation > Animation)
3. Select any GameObject (e.g. Main Camera)
4. Press “Create” button in Animation window to create Animation Clip
5. Press “Add Property” button and add any of the Properties
6. Press or hover over the circle icon on the newly added Property and observe

Actual result: Triangle icon next to the circle icon is barely visible
Expected result: Triangle icon is clearly visible

Reproducible with: 2021.3.56f1, 2022.3.66f1, 6000.0.58f1, 6000.2.4f1, 6000.3.0b1

Reproduced on: Windows 11