fix: Icon alternative fix in brand evolution branch

Description

This PR fixes the icon alternative color

Fixes:

[ ] I’ve followed MetaMask Coding Standards.
[ ] I've clearly explained what problem this PR is solving and how it is solved.
[ ] I've linked related issues
[ ] I've included manual testing steps
[ ] I've included screenshots/recordings if applicable
[ ] I’ve included tests if applicable
[ ] I’ve documented my code using JSDoc format if applicable
[ ] I’ve applied the right labels on the PR (see labeling guidelines). Not required for external contributors.
[ ] I’ve properly set the pull request status:
- [ ] In case it's not yet "ready for review", I've set it to "draft".
- [ ] In case it's "ready for review", I've changed it from "draft" to "non-draft".

[ ] I've manually tested the PR (e.g. pull and build branch, run the app, test code being changed).
[ ] I confirm that this PR addresses all acceptance criteria described in the ticket it closes and includes the necessary testing evidence such as recordings and or screenshots.