Fix type failures for native css.types.* PR (#337)

[christianbach]

Follow-up to PR #337 by @necolas to get the branch green and ready to merge.

• Align example tokens with typed vars (use Types.CSSType for colors)
• Update example createTheme overrides to css.types.color(...)

All tests (and Flow) pass locally. I don’t usually write Flow, so please sanity-check the annotations—thanks!

[christianbach]

@necolas Im suspecting that the GitHub action for benchmarks cant write I comment on this PR since its from a fork?

Note: In public repositories this action does not work in pull_request workflows when triggered by forks. Any attempt will be met with the error, Resource not accessible by integration. This is due to token restrictions put in place by GitHub Actions. 

https://github.com/peter-evans/create-or-update-comment

[necolas]

Merged in #337. Thanks for your patience