DeLorean Dark is one of the most beautiful and up-to-date GTK themes that you can use under Gnome Shell 3.6. If you don’t like dark colors though, you will be happy to know that DeLorean has a brighter brother that reached version 1.01 a few days ago.
DeLorean Light is very nicely designed by killhellokitty, looks modern, provides a metallic finish and feel and is very suitable for everyday relaxed use.
This brushed stainless steel look of DeLorean Light reminds me of the famous DeLorean DMC-12 that I suppose has been the source of inspiration for killhellokitty.
How to install
For this theme to work properly you will need to download and unzip it under /usr/share/themes. You may then select it from Gnome’s Tweak Tool. If you are using Ubuntu 12.10 you can add the following repository and automatically update to newer versions when they are available. Just type the following on a terminal:
sudo add-apt-repository ppa:killhellokitty/themes.ppa sudo apt-get update sudo apt-get install delorean-light-theme-3.6