Inconsistencies with light themes

again, after the latest update, I experienced unintended changes in themes (light/dark changes). I used the Mojave theme, but when I tried to diagnose the problems, I came across quite some inconsistencies. If somebody is out there, who knows about details, I’d be grateful for some comprehensive explanation on what changes are going on. In detail:

  • Evolution Mail turned into the dark theme after update. I can force it back to the Mojave-light theme by setting the GTK_THEME variable in /etc/environment. But basically I don’t want to clutter my system with such hacks.
  • Epiphany is coming up dark, but I can force light by adding env GTK_THEME=… to the menu shortcut.
  • LibreOffice is coming up dark. Again, I was able to force it light, but the window title bar remained dark. Could only change that by switching to the WhiteSur theme.
  • Not to talk about firefox, but I think that is a story of its own.

In conclusion, I think the inconsistencies originate from how these apps are made: snap or deb-package, Gnome or Budgie, GTK3 or GTK4. They might be transitional, as upstream is moving to GTK4? Anyways, I’d like to see some explanations about the context and status of theming and how to achieve a consistent behaviour (if at all possible). Also, some information on how to reset theming to the as-installed status would be good.

Nevertheless: thanks to all the people providing as an alternative to Window and MacOS. Big achievement!

Explanation here Theming changes in UB 22.04 and later - the TL;DR - use the gsettings trick to force these libhandy/libadwaita apps to use the light variant.