For those boring with the default login screen appearance, you may change the background wallpaper to let is shine again.
For the login screen in GNOME, the default desktop of Ubuntu & Fedora workstation, it’s not so beginner friendly. Because the settings are hidden deeply and NOT easy to configure for normal users due to permission issue. For the login background, it even does not have an option to change it.
The login screen is handled by Gnome Display Manager (aka GDM). It uses CSS (Cascading Style Sheets) file to describe how to GDM elements are displayed when you’re at login. Users used to hack the gdm3.css file to check its background. However, recent GNOME releases packed the CSS into a “
.gresource” file. Users have to extract the CSS from it, edit the file, then re-pack it into another
.gresource file and finally choose it as the GDM theme.
Thankfully, a graphical configuration tool ‘Login Manager Settings‘ is born to make the life easy. And, not only for Ubuntu, it also works for Fedora Workstation, and other Linux with GNOME 42+.
Step 1: install Login Manager Settings
The configuration tool is available to install as universal Flatpak package.
1. First, press Ctrl+Alt+T on keyboard to open terminal. Then run command to install the daemon package:
sudo apt install flatpak
Type user password when it asks for sudo authentication and hit Enter.
2. Then, install the tool by running command:
flatpak install https://dl.flathub.org/repo/appstream/io.github.realmazharhussain.GdmSettings.flatpakref
After installation, just search for and open the tool from ‘Activities’ overview.
(Optional) As you see, flatpak take hundred of MB disk spaces for run-time library. For choice, you may download the AppImage from the github releases page under ‘Assets’ section:
Then, add executable permission in file properties dialog and finally run it to launch the tool:
Step 2: Change Login Screen Background
After installed the tool, launch it. In the first ‘Appearance’ tab, select either ‘Image’ or ‘Color’ as background type.
Finally, you may either set a photo image or solid color as background of your login screen. And, click on “Apply” button to save the change.
As login screen is handled by
gdm user, you need to have administrator permission and authenticate via user password.
That’s all. Enjoy!