[WIP] Refactor theme to consolidate color definitions

[Copilot]

Thanks for the feedback on #7366. I've created this new PR, which merges into #7366, to address your comment. I will work on the changes and keep this PR's description up to date as I make progress.

Original PR: #7366
Triggering comment (#7366 (comment)):

@copilot only serika dark, darling and dots are converted on this pr. convert the rest

---

💬 We'd love your input! Share your thoughts on Copilot coding agent in our 2 minute survey.

[github-actions]

Hey there and thank you for opening this pull request! 👋🏼

We require pull request titles to follow the Conventional Commits specification and also include the author name at the end inside parenthesis. It looks like your proposed title needs to be adjusted.

Details:

No release type found in pull request title "[WIP] Refactor theme to consolidate color definitions". Add a prefix to indicate what kind of release this pull request corresponds to. For reference, see https://www.conventionalcommits.org/

Available types:
 - build
 - chore
 - ci
 - docs
 - feat
 - impr
 - fix
 - perf
 - refactor
 - revert
 - style
 - test

A correct version would look something like:

feat: add new feature (@github_username)
impr(quotes): add english quotes (@username)
fix(leaderboard): show user rank correctly (@user1, @user2, @user3)