SVG color contrast violation detected on main

The SVG color contrast check failed on `main`.

Workflow run: https://github.com/githubnext/gh-aw-workshop/actions/runs/32388829242

One or more SVG images contain text with insufficient color contrast against
its background. Brand-declared normal text requires 4.5:1; qualifying large
text and unannotated legacy SVG text require the 3:1 migration baseline.
This can make diagrams unreadable — for example, white text on a white background.

See the workflow run for the full list of violations and which files to fix.

Open workflow run 32388829242 and use its violation list to identify the affected SVG files and text/background pairs. Update the reported SVG colors to meet the stated 4.5:1 normal-text or 3:1 migration baseline, then rerun the SVG color contrast check until the workflow passes.

Written by the indexing model from the issue text.