(Flatpak) Firefox System Theme doesn't honor GNOME's mode preference


I see that Chrome based browsers doesn’t really support this on Linux but Firefox seems to have a theme that switches between light & dark mode depending on the system settings.

I have Firefox installed as flatpak and set its theme to System Setting (auto). I want Firefox to change between light & dark mode whenever I change my light/dark mode preference inside GNOME. Certain apps like Telegram (flatpak) are capable of doing that.

Is this a bug in Firefox or am I missing something?


I tested it out on my Firefox and it works, but my Firefox here is the rpm from the repos, not a flatpak. I don’t know enough about flatpaks, but perhaps it’s a limitation there or a bug in the flatpak. Is this flatpak from the Fedora registry or from Flathub? If it’s from Flathub, it’ll be best to report this issue to them (flathub.org doesn’t load for me, so I can’t find the issue link at the moment)

@ankursinha this is not working to me with firefox installed as usual via dnf, I think it was already there at install of fedora.

Have you installed something else?
I already checked e.g. the xdg-desktop-portal and it looks like I already have all of them :slight_smile:

xdg-desktop-portal.x86_64                            1.15.0-4.fc37                       @updates                                    
xdg-desktop-portal-gnome.x86_64                      43.1-1.fc37                         @fedora                                     
xdg-desktop-portal-gtk.x86_64                        1.14.1-1.fc37                       @updates                                    
xdg-desktop-portal-kde.x86_64                        5.27.2-1.fc37                       @updates                                    

Have you find a solution or the reason of the problem via Flatpak?

This looks like it works with the default theme (adwaita) on F37 with chromium based and firefox.

I do have the legacy theme set via gnome tweaks, I’m not sure if that makes a difference.

Are you using a different theme?

I experience the same, after installing the KDE environment to try it out, then uninstalling it. The RPM Firefox does not follow the system theme. I reinstalled Firefox, reset Firefox, reset the GNOME configuration but the issue still stands. I installed the flatpak Firefox and it follows the system theme. :sweat_smile:

@grumpey I have the default gnome theme.

@tannedsushi So Fedora Workstation use firefox via flatpak by default?

No, Fedora’s default is the RPM Firefox. I installed the flatpak Firefox myself to see if it has the same issue.

Excellent show for flatpak!