And also adding settings.ini to .config/gtk-3.0 && .config/gtk-4.0 with gtk-application-prefer-dark-theme=1 (which also works in 4.0 fine) - MOST things in dom0 go dark with these steps, the taskbar, most of the app windows, nautilus/thunar windows, etc.
Most things but Qube Manager. Anyone know why this might be? Does manager require a special separate setting somewhere? Does it not use GTK?
From there, the dark theme is trivial to implement. I also use debian as my default template for my appVMs. That requires a template install of gnome-tweak-tool and a few simple changes to ~/.config in corresponding appVMs to have dark themes both system wide and in your VMs.
Thank you for your answers @necker@fepitre
Unfortunately, using qt5ct didn’t solved the issue. No difference even after a reboot, the gtk2 style seems to be applied only on the “Qt5 Configuration Tool” window.
I think that I will move forward with KDE for now and hope that there is no big issue with this alternative desktop environment.
Have you tried in the same console to run qubes-qube-manager after the export? Because it works on R4.1 as explained to you. To have it persistent, you need to add the export inside e.g. in a /etc/profile.d/.
Thank you for your help, so I created a new file startup.sh in /etc/profile.d/startup.sh with the export line, and it does work only if I launch it from the terminal (by running qubes-qube-manager for example) but my “desktop” theme is still the same and any app launched from it also.
Am I missing something in your instructions ?
export QT_QPA_PLATFORMTHEME=gtk2 in /etc/environment equally does the trick, if the respective dependencies are installed. Not so important in dom0 but if you want to push it into all your templates, it’s nicer to do it this way instead of having to run qt5ct.
For me, I have Adwaita-dark selected as the theme. All vms and applications have been told to use dark theme. The Qubes programs are the only ones ignoring the setting, in dom0 or anywhere. Maybe I’m missing something?