"!" info icon in XR Plug-in Management help box has near-invisible contrast in Light theme (glyph color nearly matches its own background)

Steps to reproduce:

1. Set Editor theme to Light (Preferences > General > Editor Theme)
2. Open Project Settings > XR Plug-in Management
3. Click "Install XR Plugin Management"
4. Wait until the installation is complete
5. Observe the "!" icon in the help box at the bottom ("Information about configuration and tracking can be found below.")
6. For comparison, observe the same icon style in Project Settings > UI Toolkit > Advanced (the "Enable Event/Layout Debugger" warning boxes)

Actual results: In Light theme, the "!" glyph inside the XR Plug-in Management icon is rendered in a pale, near-white color against its own light gray circle background. This makes the icon nearly invisible. The same icon style in UI Toolkit's help boxes renders with a dark glyph against a white background.

Expected results: The "!" icon in XR Plug-in Management should render with the same dark glyph color used elsewhere (UI Toolkit and others), giving it comparable contrast in the Light theme.

Reproducible with versions: 6.0.0 ( 6000.7.0a4), 4.7.0 (6000.0.80f1, 6000.3.21f1, 6000.5.7f1, 6000.6.0b8)

Tested on (OS): MacBook Pro - Tahoe 26.6

Notes: In a dark Unite Theme, the icon looks OK