We have already seen how to install GNOME in Ubuntu 14.04. Now, if you are using GNOME Shell already, why not use a custom GNOME Shell theme? The steps are similar to installing themes in Ubuntu Unity but not entirely identical as the process to change GNOME theme is slightly different. In this quick tutorial, we shall see how to install custom GNOME Shell themes. The method should work for all the GNOME version including GNOME 3.10, 3.12 and above.
Install themes in GNOME Shell
There are two ways you can install GNOME themes.
Install themes via PPA
First is by using the official PPA of the theme. Some big projects, like Numix, provide their own PPA for easily installing the themes. For example, you can use the following commands to install Numix theme in GNOME Shell:
<code>sudo apt-add-repository ppa:numix/ppa sudo apt-get update sudo apt-get install numix-icon-theme-circle</code>
Install themes from zipped file
Not every theme designer provides a PPA. But you can always download theme pack which are often compressed. All you have to do is create a .themes directory in your home directory and extarct the theme files there.
You can do it graphically using the file manager Nautilus. Go to Home, right click, make new folder and name it .themes. Mind the dot at the start of the file name which is very important here.
Alternatively, you can use the following command to do it in command line:
Use custom themes in GNOME Shell
Once you have installed new themes, it is time to see how to use this new GNOME theme. We’ll be using Gnome Tweak Tool to switch themes. Gnome Tweak Tool is available in Ubuntu software repository. You can install it using the command below:
<code>sudo apt-get install gnome-tweak-tool</code>
Once Gnome Tweak Tool is installed, press Super key (Windows key) and search for Gnome Tweak Tool. Click on it to open it.
Now under Appearance section, you should see the options to change icons or Shell themes. You can select the themes from here.
The theme change should reflect immediately. If you do not see the theme changes immediately, press Alt+F2 key. It will open the command box. Just type ‘r’ in it. This will restart the GNOME shell and the selected theme will be applied.
Possible troubleshoot: Not able to select GNOME Shell theme
It might happen that you see an exclamation mark and you might not be able to select themes in it. Some what like this:
Don’t worry. It’s not a big deal. You need to install Gnome Shell Extensions to fix this issue. Use the following command in terminal:
<code>sudo apt-get install gnome-shell-extensions</code>
After installing the extensions, go to Extensions->User Theme and turn it on.
Now, you should be able to install the themes as described earlier.
You can get plenty of GNOME Shell themes from GNOME LOOK. But beware that not all themes might be compatible with your version of GNOME Shell. I hope this helps you to easily and correctly install themes in GNOME Shell. Any questions or suggestions are always welcomed.