Install GNOME 3 (GNOME Shell Or Classic) GTK / Mutter / Metacity Themes

In the latest GNOME 3, changing the theme isn't as easy as you're used to. Using Gnome Tweak Tool you can change the GTK theme but how about the titlebar (Mutter/Metacity theme)? Read on!

How to install GNOME3 GTK themes

To change the GTK theme in GNOME 3 (with or without GNOME Shell), you can use Gnome Tweak Tool which is available in the GNOME 3 Ubuntu PPA, Fedora 15 official repositories, etc. If you're using Ubuntu 11.04 and the GNOME 3 PPA, run the following command to install it:

sudo apt-get install gnome-tweak-tool

To be able to use a GTK theme, make sure it's installed in /usr/share/themes/ and not in ~/.themes/ as Gnome Tweak Tool doesn't display the themes found in ~/.themes.

Then, to change the GNOME3 GTK theme, open Gnome Tweak tool and select the theme you want to use on the "Interface tab":

On the same tab in Gnome Tweak Tool you can also change the icon theme. But please note that the top panel icons in GNOME Shell will not change when chaging the icon theme (however, if you're using the classic GNONE 3 panels, the icons will change everywhere).

How to install Mutter (titlebar) GNOME Shell theme

To be able to change the GNOME 3 Mutter theme (I hope that's how it's called now) - that's the titlebar theme in GNOME Shell -, you need to install the theme under the ~/.themes folder. Yes it's weird, but that's how it works right now, hopefully this will change in future GNOME 3 releases.

Then, to change the GNOME Shell titlebar theme you need to edit some gconf settings so press ALT + F2 and enter: "gconf-editor" (if not installed, search for gconf-editor in your Linux distribution repositories) and navigate to desktop > shell > windows and change the "theme" value with the name of the theme you want to use:

The changes don't take effect immediately so you'll have to logout for the changes to take effect, or press ALT + F2 and enter: "r".

Important: for the "theme" value, enter the folder name of the theme you've copied to your ~/.themes folder. So if you've installed the Elementary theme under ~/.themes/egtk folder, use "egtk" for the "themes" key value.

How to change The Metacity theme in GNOME 3 (classic)

If you use the classic GNOME3 desktop, changing the titlebar (Metacity) theme is different then changing it for GNOME Shell. First of all, you don't have to copy the theme under ~/.themes/, it will work with /usr/share/themes/ too.

To change the Metacity theme in the GNOME 3 classic desktop (with GNOME panels), press ALT + F2, enter "gconf-editor", navigate to apps > metacity > general and change the "theme" value to the name of the theme you want to use:

Update: for switching GNOME Shell themes easily (not GTK themes - GNOME Shell themes are different), see: ThemeSelector: GNOME Shell Extension To Change Themes (With Previews)

The instructions in this post were tested on Fedora 15 beta (with GNOME Shell), GNOME Shell built using jhbuild in Ubuntu 11.04 and the classic GNOME3 session in VirtualBox.