Steps to replicate the issue (include links if applicable):
I was recently working on a prototype UI which used Codex components outside of MediaWiki (I have a basic Vue SPA prototyping environment).

When displaying a dialog that contains inline Radio groups with Label components, I noticed that the label text was not switching properly when the dark color mode was active:

What happens?:

It seems like the color: @color-base rule is not set on either the Label component, or the Radio component.

What should have happened instead?:
We should probably set the base color for textual elements like Labels (we do this for Buttons). I assume global styles in MediaWiki do set this up, which is why we don't see this bug there.

Software version (on Special:Version page; skip for WMF-hosted wikis like Wikipedia):
Codex 2.3.3