How to change theme in Ubuntu 16.04/17.10?

Two types of themes

• Shell theme – Stored or installed in ~/.themes/ directory. Shell themes are themes for the shell.
• GTK3 theme – Stored or installed in /usr/share/themes/ directory. GTK3 themes are themes for applications.

Procedure to change the theme in Ubuntu

1. Install gnome-tweak-tool by typing:  sudo apt install gnome-tweak-tool
2. Install or download additional themes
3. Start gnome-tweak-tool
4. Select Appearance > Themes > Choose theme Applications or Shell from the drop-down menu

Let us see all steps in details.

Step 1. Install gnome-tweak-tool

Open the terminal application and type the following apt command / apt-get command:

$ sudo apt update
$ sudo apt install gnome-tweak-tool

$ sudo apt install gnome-shell-extensions

Step 2. Create directories

To store themes/icon files create the following directories using the mkdir command:

$ mkdir -v ~/.{themes,icons}

Step 3. Install theme on Ubuntu

You can install or search GTK 3 themes using apt command:

$ apt search theme
$ apt search theme | grep arc
$ sudo apt install arc-theme

HOW TO DOWNLOAD SHELL THEMES

To grab shell themes (or GTK3/2 themes) from the Internet and download it with the wget command:

$ cd ~/.themes/
$ cd /tmp/
$ wget https://github.com/daniruiz/Flat-Remix-GNOME-theme/archive/master.zip
$ unzip master.zip
$ mv flat-remix-gnome-master/Flat-Remix/ ~/.themes/
$ gsettings set org.gnome.shell.extensions.user-theme name "Flat-Remix"

Step 4. How to change the theme in Ubuntu 16.04/17.10

Start gnome-tweak-tool by typing the following command:

$ gnome-tweak-tool &