Hello world,
happy new year!
grey on black is unreadable in dark modes (both default or dark theme), best to see in submenu Folder > Properties > Retention Policy
That is confusing / unreadable! 
Beta 85.0b2
Is this posted here at the right spot?
cheers, have a good one.
Assuming you haven’t got any userChrome customisations (and if you don’t know then you haven’t) then I suggest you look at the bugs already raised for ‘dark mode’:
https://bugzilla.mozilla.org/buglist.cgi?product=Thunderbird&short_desc=dark%20mode%20&query_format=advanced&short_desc_type=allwordssubstr&resolution=---&classification=Client%20Software&classification=Developer%20Infrastructure&classification=Components&classification=Server%20Software&classification=Other
You may see something similar. If not you could raise a new bug and attach that screenshot. It certainly looks like a bug.
Well done 
Your first bug I see.
Don’t expect action quickly!
