I plan to write about themes from time to time so I thought it would be a good idea to start with an article explaining how to change the theme, so it’s clear for everyone. I’ll start with GNOME, and maybe expand this later on.To be able to change the GTK and icon themes in GNOME (Shell), you’ll need to install an application called Tweaks (a while back it was called GNOME Tweak Tool). The application should be available in your Linux distribution repositories, so simply search for it and install it.In Debian (Sid or newer) and Ubuntu (18.04 and newer), install Tweaks by using the following command:
sudo apt install gnome-tweaks
For older Debian and Ubuntu versions, install GNOME Tweaks Tool using the command below:
sudo apt install gnome-tweak-tool
In Fedora you can install GNOME Tweaks using:
sudo dnf install gnome-tweaks
At this point, you’ll be able to change the GTK and icon themes using the Tweaks application, on the Appearance tab:To be able to change the GNOME Shell theme, you’ll need the User Theme GNOME Shell extension.
To install this in Ubuntu or Debian, use the following command:
sudo apt install gnome-shell-extensions
On Fedora, install the GNOME Shell User Theme extension with:
sudo dnf install gnome-shell-extension-user-theme
After installing it, restart GNOME Shell if you’re using Xorg by pressing Alt + F2, then type r and press Enter. Or logout and login to restart the session if you’re using Wayland.
Next, open the Tweaks app and enable the User themes extension:
Now you should be able to change the GNOME Shell theme: