Use GDM Settings to Customise Ubuntu’s Login Screen

Ubuntu, like other Linux distributions uses the GNOME Display Manager (GDM) as its, well, display manager, though most of us tend to think of or refer to it as the login screen.

To customise the Ubuntu login screen, such as setting a different theme or icon set, changing the login screen background image or colour, or getting night light to apply when viewing it, you can use a 3rd-party tool called GDM Settings.

GDM Settings app — Appearance options galore

The app is written in Python and uses libadwaita for its UI, so it looks great on the modern Ubuntu desktop and adapts gracefully when resizing the window or running on width-constrained displays.

GDM Settings lets you:

Set login screen background image/colour
Change login screen theme, icons, and cursor
Change font, font sizes, and scaling factor
Show battery percentage in login screen
Customise top bar text and background colours
Set mouse/touchpad behaviours
Enable/disable on-screen options (e.g., user list)
Power settings (e.g., dim screen, screen timeout)
Enable Night Light support

Plus a fair bit more.

The “big” thing:

GDM Settings is not an official GNOME tool. Use it cautiously, at your own risk. I get the impression a few of the tweaks/options available in the app aren’t adjusting intentionally configurable values, or alter hardcoded settings ad-hoc.

Indeed, I have also seen reports of people using this tool to do something seemingly safe, like change the colour of the login screen, only to find that GDM fails to load after, throwing the frustrating “Oh no! Something has gone wrong” error screen.

Again: use this at your own risk.