Install GnomishDark theme on Ubuntu 12.10/12.04/11.10/Mint

Install GnomishDark theme on Ubuntu 12.10 Quantal/Ubuntu 12.04 Precise/Ubuntu 11.10 Oneiric/Linux Mint

GnomishDark is clean theme for gtk, It also includes theme for Gnome Shell. This is designed for those people who like dark themes. It is compatible with Gtk 3.6/3.4/3.2 and Gnome Shell 3.6/3.4/3.2.

Theme tested on Ubuntu 12.10 Quantal with Gnome Shell 3.6 and Gtk 3.6, Also checked with Gtk 3.4 and Gnome shell 3.4

New fixes in this theme:

• Sleeker scrollbars.
• Fixed Evolution's contacts.
• Added missing images to the shell folder.
• Fixed user avatar.

Recommended: Install NouveGnome Icons or Check icons collection
You can use Gnome-tweak-tool or Ubuntu-Tweak to change themes.

To install GnomishDark theme on Ubuntu/Linux Mint open Terminal (Press Ctrl+Alt+T) and copy the following commands in the Terminal:

Terminal Commands:
sudo add-apt-repository ppa:noobslab/themes
sudo apt-get update
sudo apt-get install gnomishdark

That's it

Source: GnomishDark