Evolve is a new, simplistic GNOME 3 theme created by the Ambiance Blue author. The theme is compatible with the latest GTK 3.2 and uses the Adwaita engine for the GTK3 theme and Murrine for the GTK2 theme:

Evolve GTK theme

If you use Ubuntu 11.10 Oneiric Ocelot , you can install Evolve by adding the WebUpd8 Themes PPA:

sudo add-apt-repository ppa:webupd8team/themessudo apt-get updatesudo apt-get install evolve-gtk-theme

For other Linux distributions, download Evolve via DeviantArt.

Sonar is a GTK3 port of the beautiful Sonar theme which is used by default in openSUSE. The theme comes with a GTK2 version too and is compatible with GNOME 3.2 (there’s also a GNOME 3.0 version available in the DeviantArt package – not available in the WebUpd8 PPA because it’s not compatible with Ubuntu 11.10 Oneiric Ocelot).

Sonar GTK3 theme

Install Sonar GTK2/3 theme in Ubuntu 11.10 Oneiric Ocelot using the commands below: 

sudo add-apt-repository ppa:webupd8team/themessudo apt-get updatesudo apt-get install sonar-gtk-theme

If you’re not using Ubuntu, download Sonar GTK3 via DeviantArt.

Elegant Brit is a cool, unique theme that is now available for GNOME 3.2.

Elegant brit

The Elegant Brit pack includes a GTK2, GTK3 and a GNOME Shell theme. Install them all in Ubuntu using the commands below:
sudo add-apt-repository ppa:webupd8team/themessudo apt-get updatesudo apt-get install elegant-brit-gtk-theme

If you’re not using Ubuntu, download Elegant Brit GTK3 via DeviantArt.

Elements is a beautiful light GTK3 theme based on elementary theme. The theme comes with two variants: one tweaked for GNOME Shell and GNOME Classic and one optimized for Unity.

Elements GTK3 theme

To install Elements in Ubuntu 11.10 Oneiric Ocelot, firstly add the WebUpd8 Themes PPA:
sudo add-apt-repository ppa:webupd8team/themessudo apt-get update

And then install the version you want:

- Elements for GNOME Shell and Classic GNOME: 

sudo apt-get install elements-gs-theme

- Elements for Unity: 

sudo apt-get install elements-unity-theme

If you’re not using Ubuntu, download Elements via Gnome Look.

How to apply a new theme

To use any of the above themes, you’ll need GNOME Tweak Tool. To install it in Ubuntu, use the command below:

sudo apt-get install gnome-tweak-tool

Then search for GNOME Tweak Tool in Dash / Activities (it shows up as “Advanced Settings”) and using it, apply a new theme from the themes tab. Make sure you apply the theme for both GTK and window theme.
If you don’t want to use GNOME Tweak Tool, you can change the themes using the command line:

- for Metacity themes: 

gconftool-2 -s --type string /apps/metacity/general/theme "theme-name"

- For GTK3 themes: 

gsettings set org.gnome.desktop.interface gtk-theme "theme-name"

You can find the exact theme names by navigating to /usr/share/themes/.

When changing the window theme in GNOME Shell, you’ll have to reload it to apply the new theme (sometimes this is required for Unity too): press ALT + F2 and enter “r” or log out and log back in.


Web Upd8 – Ubuntu / Linux blog