The hover selection/highlight of items in the Insert button dropdown and the Documentation button dropdown are hard to see when hovered using the Light Editor theme

Steps to reproduce:

1. Create a new Unity project using the Universal 3D template
2. Install the Visual Effect Graph package (com.unity.visualeffectgraph)
3. Create a new VFX Graph (Assets > Create > Visual Effects > Visual Effect Graph)
4. Open the newly created VFX Graph
5. Click on the Documentation button dropdown on the top right side of the VFX Graph window
6. Hover the mouse cursor over the items in the dropdown
7. Observe the selection/highlight of the items when hovered

Actual results: The hover selection is hard to see

Expected results: The hover selection is clearly visible

Reproducible with versions: 6000.0.38f1, 6000.0.73f1, 6000.3.13f1, 6000.4.3f1, 6000.5.0b4, 6000.6.0a3

Not reproducible with versions: 6000.0.37f1

Tested on (OS): MacOS Silicon Tahoe 26.3