Use https://extensions.gnome.org/extension/4998/legacy-gtk3-theme-scheme-auto-switcher/ to automatically sync with dark mode with legacy apps
Is it installed via flatpak?
If so, have you installed the package org.gtk.Gtk3theme.Adwaita-dark?
I think Geary still GTK 3
No, I installed it with pacman on Arch. I tried to install https://aur.archlinux.org/packages/adwaita-dark for gtk2, but it is not working.
Or at least I don't know where to switch themes for GTK2.
GNOME Tweaks > Appearance > Legacy Applications
Thanks! That did it!
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