I don't know what to do. I use Tunderbird 64-bit beta on Windows 10. In windows settings, I use a dark mode for Windows and a light mode for apps. In V81 beta things looked fine. Then came an upgrade to V82 beta. Now several things look odd: a) I use themes, currently the «Autumns Light by Madonna». It only works partly now, see attached image. b) In the list of emails, unread emails used to be in bold black on white. Now they are white on white, which is a bit hard to read. c) Symbols in front of folder names do not show any more, except for the currently chosen folder. Or perhaps they are in white on white. d) In a new mail window, the main text area uses white text on dark background. I can of course read that, but it should have been dark on white. e) In the calendar, saturdays and sundays have a darker background than before, not the light green. It doesn't look good, and I don't think it was meant to be this way. It seems like a lot of things have been screwed up in going from 81 to 82 beta. I tried to go back to 81 beta, but then Thunderbird wouldn't accept my profile any more. Maybe I should report this as a bug, but I don't know where or how to do that. Knut Arnold Kvalsvik