Dark Mode doesn't work when using non-standard themes like "Adw-Dark" instead of Adwaita

[DebanjanBarman]

Dark mode isn't working

.

[kocio-pl]

Try to change system style and give a reply what happens. I have dark style in my system and I have the opposite problem - GTG is always dark, no matter what are the application settings.

[daniel-sanchez-marzoa]

Hi, had the same problem but I already have dark style in my system, and gtg is still light

[Neui]

What distribution do you use? Do you use some custom style? Try executing GTG with GTK_DEBUG=interactive (like GTK_DEBUG=interactive flatpak run org.gnome.GTG for the flatpak version, GTK_DEBUG=interactive gtg for a locally installed version), and check the Visual tab in the new window.

It should tell you the GTK3 theme (where you can also switch) and whenever darkmode is enabled. Note that the Dark Mode in GTG settings should change that dark mode settings in visual tab, but not the other way around.

Here is me trying it out GTG (flatpak) on Fedora 36 beta live CD in a VM:

[Chrysostomus]

I ran into the same issue on Manjaro with the flatpak version. I think I have identified the issue: the gtk-theme we are using is Adw-dark that mimics the libadwaita theme. This makes regular gtk3 apps look like libadwaita apps, but because the corresponing flatpak theme is not installed, gtg does not know what to do and the gtk theme in interactive debugging is unset.

The solution is to install the corresponding flatpak theme.

[daniel-sanchez-marzoa]

I can confirm it was a problem with the theme I was using in Gnome. Switching back to the default Adwaita-dark fixed the problem. Thanks for the help

[Nesaijn]

I had the same reason for this issue. The entry in the "Visual" tab for "GTK+ Theme" was empty since I did set another theme in gnome tweaks for legacy applications. Setting it to "Adwaita" fixed it.

An idea to fix this is to set "Adwaita" as a default for the entry "GTK+ Theme" for cases like these.

EDIT:
Another workaround or fix as the already mentioned ones for the Flatpak version, is setting the GTK_THEME environment for GTG, for example in Flatseal. GTK_THEME=Adwaita did not work as it always used the light version so GTK_THEME=Adwaita:dark was the way to go for me.

[nekohayo]

Closing as you folks found a workaround for your custom theme problem.

In the long term, the solution for this would be #608 (including #576 + #844).