fix(color): preserve Ionic color attributes

[rdlabo]

Summary

• keep Ionic color attributes effective for inset-list header labels and item-group header icons
• retain existing theme defaults only when color is not specified
• add default and colored comparison patterns to /main/index/item-list

Verification

• npm run lint
• npm run build
• demo production build
• browser computed-style checks for default and colored labels, icons, and notes
• manager review approved
• OSS maintainer review approved

Screenshot binaries are intentionally excluded because local macOS rendering differs from Linux CI.

[github-actions]

Playwright test results

 78 passed

Details

 78 tests across 1 suite
 1 minute, 29 seconds
 61c671e
 This detailed result covers Ionic 9 only. Ionic 8 runs against the same screenshots in a separate matrix job; check the workflow run for both results. To update the screenshots, comment with /update-screenshots.

[github-actions]

📊 Ionic 9 Playwright Test Report

View the detailed Ionic 9 report: https://rdlabo-dev.github.io/ionic-theme-md3/pr-42/

Ionic 8 runs against the same screenshots in a separate matrix job. View both results in the workflow run.

[rdlabo]

/update-screenshots

[github-actions]

✅ Screenshots have been updated successfully!

The new screenshots have been committed to this PR.

[github-actions]

📊 Ionic 9 Playwright Test Report

View the detailed Ionic 9 report: https://rdlabo-dev.github.io/ionic-theme-md3/pr-42/

Ionic 8 runs against the same screenshots in a separate matrix job. View both results in the workflow run.

[github-actions]

npm beta published

CI passed for the merge commit fa986f7d84d2. Install the immutable version with:

npm install @rdlabo/ionic-theme-md3@9.1.0-beta.pr42.shafa986f7d84d2