chore: Refactor visual accent colors to use tokens

[at-susie]

Description

This PR refactors the visual accent styling for the Box and Badge components.

Changes

• Removed some unnecessary color options
• Refactored visual accent colors and badge component's style to use explicit token references
• Added hexToRgba utility for color handling
• Updated visual accent styles

Related links, issue #, if available: n/a

How has this been tested?

Review checklist

The following items are to be evaluated by the author(s) and the reviewer(s).

Correctness

• Changes include appropriate documentation updates.
• Changes are backward-compatible if not indicated, see CONTRIBUTING.md.
• Changes do not include unsupported browser features, see CONTRIBUTING.md.
• Changes were manually tested for accessibility, see accessibility guidelines.

Security

• If the code handles URLs: all URLs are validated through the checkSafeUrl function.

Testing

• Changes are covered with new/existing unit tests?
• Changes are covered with new/existing integration tests?

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[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 97.60%. Comparing base (c8a9b3b) to head (e655361).
⚠️ Report is 1 commits behind head on main.

Additional details and impacted files

@@           Coverage Diff           @@
##             main    #4745   +/-   ##
=======================================
  Coverage   97.60%   97.60%           
=======================================
  Files         951      951           
  Lines       30742    30742           
  Branches    11278    11279    +1     
=======================================
  Hits        30005    30005           
+ Misses        730      690   -40     
- Partials        7       47   +40     

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