I am not sure who maintains this but I will happily review any patch that attempts to fix this! Thanks for the report!

Change #1055641 had a related patch set uploaded (by Theprotonade; author: Theprotonade):

[mediawiki/core@master] Make debug toolbar dark mode compatible

https://gerrit.wikimedia.org/r/1055641

Hi @Jdlrobson, I just put in a patch for this. However, do you think the rest of the CSS (apart from the colours) needs to use the codex tokens too (like border width, perhaps)? Maybe that is for a different task? :)

I don't like the design changes currently proposed in the patch. The debug toolbar is not exactly a pinnacle of visual design, but I think this makes it worse. In particular, useful visual distinctions are removed (e.g. between table headers and cells, or between the debug bar itself and the background of the page), while trivial ones are emphasized (e.g. between odd and even table rows). I hope we can find some Codex tokens that do a better job.

Before	After

Thanks for the review @matmarex, I have changed my patch with tokens that match the initial colours better.

Thanks, I think it looks much better! Screenshots of the final version for reference:

Before	Final

Change #1055641 merged by jenkins-bot:

[mediawiki/core@master] Make debug toolbar dark mode compatible

https://gerrit.wikimedia.org/r/1055641