Steps to replicate the issue (include links if applicable):

• Go to https://en.wikipedia.org/w/index.php?title=Draft:Sandbox&direction=prev&oldid=1224980500&vectornightmode=1&safemode=1
• Look at the line of text in the page

What happens?:
The text color is the default text color for light mode.
What should have happened instead?:
Text color should have been the defalt text color for night mode.
Software version (on Special:Version page; skip for WMF-hosted wikis like Wikipedia):

Other information (browser name/version, screenshots, etc.):
The MediaWiki software autocorrects text color to #333 if background-color is defined but color is not (T358797). This is done to ensure proper color contrast for night mode. However, when background-color is defined using a CSS variable (e.g. Codex tokens), this is not necessary, and in fact causes color contrast issues of its own. https://www.mediawiki.org/wiki/Recommendations_for_night_mode_compatibility_on_Wikimedia_wikis suggests defining only background-color is acceptable as long as CSS variables are used.