[Evolution] Dark theme is gone since last update

Support GNOME
2

That is the known issue, you are not alone.

There is 2 different solutions:

1. solution:
Switch to some compatible dark theme e.g. Adw-dark

OR

2. solution:

Evolution still supports the environment variable GTK_THEME=<Your theme>

  1. copy the original desktop app to your own desktop app:
cp /usr/share/applications/org.gnome.Evolution.desktop ~/.local/share/applications/
  1. Edit ~/.local/share/applications/org.gnome.Evolution.desktop to change all Exec
Exec=bash -c 'GTK_THEME=<Your theme> /usr/bin/evolution'