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asterix

Member

Registered: 2025-09-15

Posts: 10

[SOLVED] Firefox ESR 140 does not play well with XFCe themes

I have a Arch based distro that I am using with XFCe 4.20. The GTK version is 3.24. When I apply XFCe themes then that does not get reflected on Firefox 140 ESR. For example see the book marks popup window in the attached image for more details. It is almost fully transparent and not opaque at all.

Similar behaviour is observed when I group a few tabs together into a group and I want to modify the group then also the popup is almost fully transparent and not opaque. Please see the uploaded screenshots for more details.

This is not observed for menu items only for popups.

I have enabled the Title Bar and restarted the browser and still the same issue.
I have set the theme to "System Theme-auto" and still the same issue. If I put the theme to Light or other themes the same behavior is observed.
I have changed in the config file $HOME/.config/gtk-4.0/settings.ini the value of gtk-application-prefer-dark-theme to zero, restarted the browser and still the same issue.

How do I resolve this issue?

Added later 26 min 34 s:
Dont know if this helps. I have tried it with Arc theme. As well as Adwaita. Both of them are light themes and both of them have the same issue.

Last edited by asterix (2025-09-16 11:49:41)

ToZ

Administrator

From: Canada

Registered: 2011-06-02

Posts: 12,304

Re: [SOLVED] Firefox ESR 140 does not play well with XFCe themes

Hello and welcome.

Do you have the opacity for popup windows set to a low value at Settings Manager > Window Manager Tweaks > Compositor tab? (However, this should affect all popups).

Also, do you have an ~/.config/gtk-3.0/gtk.css file and if so, what is the content?

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asterix

Member

Registered: 2025-09-15

Posts: 10

Re: [SOLVED] Firefox ESR 140 does not play well with XFCe themes

I have checked the opacity value in "Window Manager Tweaks" and all of them are at maximum. Also I have selected all the values under "Enable Digital Composting" Please see the uploaded screenshot for more details.

About the file ~/.config/gtk-3.0/gtk.css, yes I have that file. In fact I have the following structure

~/.config
   |--> gtk2
   |     |--> gtkfilechooser.ini  
   |--> gtk3
   |     |--> gtk.css
   |     |--> settings.ini
   |--> gtk4
   |     |--> gtk.css
   |     |--> settings.ini
   |     |--> libadwaita.css
   |     |--> libadwaita-tweaks.css

The contents of the file ~/.config/gtk-3.0/gtk.css are given below.

.mate-panel-menu-bar button {
    color: transparent;
}
panel-toplevel.background.horizontal,
.mate-panel-menu-bar,
#clock-applet-button,
#clock-applet-button:hover  {
    color: white;
}
#tasklist-button {
    color: white;
}

While the contents of the file ~/.config/gtk-4.0/gtk.css are given below

/* GTK NAMED COLORS ---------------- use responsibly! */
@define-color accent_bg_color @blue_3;
@define-color accent_fg_color #eaeaea;
@define-color accent_color #78aeed;
@define-color destructive_bg_color @red_4;
@define-color destructive_fg_color #eaeaea;
@define-color destructive_color #ff7b63;
@define-color success_bg_color @green_5;
@define-color success_fg_color #eaeaea;
@define-color success_color @green_1;
@define-color warning_bg_color #cd9309;
@define-color warning_fg_color rgba(0, 0, 0, 0.8);
@define-color warning_color @yellow_2;
@define-color error_bg_color @red_4;
@define-color error_fg_color #eaeaea;
@define-color error_color #ff7b63;
@define-color window_bg_color #323131;
@define-color window_fg_color #eaeaea;
@define-color view_bg_color #1e1e1e;
@define-color view_fg_color #eaeaea;
@define-color headerbar_bg_color #303030;
@define-color headerbar_fg_color #eaeaea;
@define-color headerbar_border_color #eaeaea;
@define-color headerbar_backdrop_color @window_bg_color;
@define-color headerbar_shade_color rgba(0, 0, 0, 0.36);
@define-color headerbar_darker_shade_color rgba(0, 0, 0, 0.9);
@define-color sidebar_bg_color #303030;
@define-color sidebar_fg_color #eaeaea;
@define-color sidebar_backdrop_color #2a2a2a;
@define-color sidebar_shade_color rgba(0, 0, 0, 0.36);
@define-color secondary_sidebar_bg_color #2a2a2a;
@define-color secondary_sidebar_fg_color #eaeaea;
@define-color secondary_sidebar_backdrop_color #272727;
@define-color secondary_sidebar_shade_color rgba(0, 0, 0, 0.36);
@define-color card_bg_color rgba(255, 255, 255, 0.08);
@define-color card_fg_color #eaeaea;
@define-color card_shade_color rgba(0, 0, 0, 0.36);
@define-color dialog_bg_color #383838;
@define-color dialog_fg_color #eaeaea;
@define-color popover_bg_color #383838;
@define-color popover_fg_color #eaeaea;
@define-color popover_shade_color rgba(0, 0, 0, 0.36);
@define-color thumbnail_bg_color #383838;
@define-color thumbnail_fg_color #eaeaea;
@define-color shade_color rgba(0, 0, 0, 0.36);
@define-color scrollbar_outline_color rgba(0, 0, 0, 0.5);

@import 'libadwaita.css';
@import 'libadwaita-tweaks.css';

Should I create a symbolic link between ~/.config/gtk-3.0/ and ~/.config/gtk-4.0 ? Where ~/.config/gtk3.0 is the link pointing to ~/.config/gtk4.0? Will that solve the problem?

Please do let me know if the settings.ini file is required from both ~/.config/gtk-3.0/ and ~/.config/gtk-4.0/ directory.

Dont know whether this helps or not, but Firefox 140.x ESR depends on GTK3, GLIB2, gdk-pixbuf2, libx11, libxcb, libxcomposite and a few others. Have not checked the issue with other applications like HexChat and a few others.

Edit 1: If the linking of the ~/.config/gtk-3.0 and ~/.config/gtk-4.0 is not recommended or will not solve the problem, then can the linking of the gtk.css files or settings.ini file help? I can make the file ~/.config/gtk-3.0/gtk.css as a symbolic link to ~/.config/gtk-4.0/gtk.css. Or vice-versa.
And I can make the file ~/.config/gtk-3.0/settings.ini a symbolic link to ~/.config/gtk-4.0/settings.ini

Added later 4 h 01 min 43 s:
I did a simple test. My existing XFCe Theme was Arc. I changed the theme to Adwaita theme. This change was done in Settings > Appearance.

There were no changes made to the Settings > Window Manager > Style > Theme. Prior to change to Adwaita, the theme in Window Manager was Arc and post the change to Adwaita the Window manager style theme was still Arc.

I observed that there was no change in the settings file of ~/.config/gtk-3.0/settings.ini as well as ~/.config/gtk-4.0/settings.ini. In both of these settings file the value of gtk-theme-name key was Arc prior to change and post change.

This change was observed after logging off from the XFCe windows session and then logging in back. No Restart.

Is this normal and expected behaviour? Shouldn't the change of theme have a corresponding change in settings.ini file too ? Is this related to the issue that is being observed?

Last edited by asterix (2025-09-16 03:39:10)

ToZ

Administrator

From: Canada

Registered: 2011-06-02

Posts: 12,304

Re: [SOLVED] Firefox ESR 140 does not play well with XFCe themes

Should I create a symbolic link between ~/.config/gtk-3.0/ and ~/.config/gtk-4.0 ? Where ~/.config/gtk3.0 is the link pointing to ~/.config/gtk4.0? Will that solve the problem?

No it won't. As you note, firefox is using gtk3 not gtk4.

Please do let me know if the settings.ini file is required from both ~/.config/gtk-3.0/ and ~/.config/gtk-4.0/ directory.

Its optional - it can include some gtk3 configurations.

And I can make the file ~/.config/gtk-3.0/settings.ini a symbolic link to ~/.config/gtk-4.0/settings.ini

Best to keep them separate.

Is this normal and expected behaviour? Shouldn't the change of theme have a corresponding change in settings.ini file too ? Is this related to the issue that is being observed?

No. Xfce manages this information in it's xfconf database - see the xsettings channel in xfce4-settings-editor.

In firefox, go to the "about:config" page and try setting "gfx.webrender.force-disabled" to true, to see if it helps.

If not, try creating a second user on your computer to see if the problem persists there. If not, it may have something to do with your firefox profile.

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Mark solved threads as [SOLVED] to make it easier for others to find solutions.
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asterix

Member

Registered: 2025-09-15

Posts: 10

Re: [SOLVED] Firefox ESR 140 does not play well with XFCe themes

Should I create a symbolic link between ~/.config/gtk-3.0/ and ~/.config/gtk-4.0 ? Where ~/.config/gtk3.0 is the link pointing to ~/.config/gtk4.0? Will that solve the problem?

No it won't. As you note, firefox is using gtk3 not gtk4.

Please do let me know if the settings.ini file is required from both ~/.config/gtk-3.0/ and ~/.config/gtk-4.0/ directory.

Its optional - it can include some gtk3 configurations.

And I can make the file ~/.config/gtk-3.0/settings.ini a symbolic link to ~/.config/gtk-4.0/settings.ini

Best to keep them separate.

Is this normal and expected behaviour? Shouldn't the change of theme have a corresponding change in settings.ini file too ? Is this related to the issue that is being observed?

No. Xfce manages this information in it's xfconf database - see the xsettings channel in xfce4-settings-editor.

In firefox, go to the "about:config" page and try setting "gfx.webrender.force-disabled" to true, to see if it helps.

In Firefox about:config the key gfx.webrender.force-disabled was not defined. So I created a boolean value for for it with the value of true. Restarted and checked that did not resolve the issue.

If not, try creating a second user on your computer to see if the problem persists there. If not, it may have something to do with your firefox profile.

I did not create a second Linux user but I went to Menu > Troubleshooting mode and started Firefox in that. That worked, the issue was no longer happening.
I created a new Firefox profile and started with that. Then started the painful process of redoing, step by step, all the customization that was done my primary/main profile. Finally I found the cause. There was an option in Look & Feel > Appearance > Enable panel transparency, as soon as I enabled it the issue reoccurred in my new profile. So went back to my main/primary profile and undid the option and it worked, the issue was resolved. It was not a XFCe issue but a configuration issue with Firefox.

Thanks ToZ