I also see it was mentioned here previously in the forums:
So I did some digging. It looks like Electron does have a fix for this issue, as long as we do not use a prebuilt version, as it is an optional flag in the build process: enable_win_dark_mode_window_ui to true in buildflags/buildflags.gni
I'm afraid building Electron from sources might cause hard to debug issues. For example we have one caused by rebuilding just sqlite and Electron is probably an order of magnitude more complex.
Please don't change this! Is this really an issue? My Joplin looks like this and I love it
The title bar color apparently is taken from the chosen Accent color (a Windows setting). So I'd say it's a feature, not a bug.
People who want this fixed will probably want to pick a darker accent color anyway.
(you can also check 'pick from background', which is what I usually do - that way if you have a rotating set of dark-ish backgrounds, you get a rotating set of nice accent colors that change from time to time.)
It's hard to say which issues are good as without doing some analysis, as you've just discovered. Any issue labelled medium or high is ok to take.
For example: