If you find difficulties enabling or installing Gnome Shell themes under Ubuntu 12.04 LTS Precise Pangolin, then this tutorial will be useful for you. Before we start, you should know that this tutorial is about Gnome Shell themes not GTK+ themes because they are totally different.
A Gnome Shell theme has this directory tree structure:
- theme folder name
- - gnome-shell
The "gnome-shell" folder contains all theme images and files. Let's now start our tutorial:
1. Installing and Enabling Gnomle Shell
If you haven't already installed Gnome Shell under Ubuntu 12.04, then do with this command from the terminal:
sudo apt-get install gnome-shell
Logout and select GNOME from the session menu and log back in to start Gnome Shell:
2. Installing Gnome Tweak Tool
Gnome Tweak Tool is an application that allows us to mange Gnome Shell themes and extensions. To install it under Ubuntu 12.04, run this command from the terminal:
sudo apt-get install gnome-tweak-tool
3. Installing Gnome Shell Extensions
To be able to use Gnome Shell themes, you need to install Gnome Shell Extensions by running this sequence of commands:
sudo add-apt-repository ppa:upubuntu-com/gnome3
sudo apt-get update
sudo apt-get install gnome-shell-extensions
When you finish the installation, reset Gnome Shell as follows:
ALT + F2 -> r > Enter
4. Enabling GNOME Shell User Themes Extension
Start now Gnome Tweak Tool and in the Shell Extensions tab turn on "User Themes Extension":
Close now the Gnome Tweak Tool window and reset again Gnome Shell:
ALT+F2 -> r -> Enter
Start again Gnome Tweak Tool and open now the "Theme" tab. You will notice that the "Shell theme" option is now enabled:
Let's now go to the last step.
5. Installing A Gnome Shell Theme
All Gnome Shell themes must be placed in the .themes folder. This hidden folder must be created in the home directory. You can easily create it with this command from the terminal:
Note: To display hidden folders under Ubuntu, press CTRL+H while browsing a folder via Nautilus.
Then all downloaded themes must be extracted there. We will use as an example the installation of the "Flat And Square" GNOME Shell theme, you can download it from here. Extract the theme contents to the ".themes" folder:
Start now Gnome Tweak Tool and head to the Theme tab and select the "Flat And Square" theme from the dropdown menu to enable it:
Note: You can also use the browse button provided in Gnome Tweak Tool to install and enable Gnome Shell themes.
I hope you find this tutorial helpful, and have a nice day!