Open the terminal and run this sequence of commands to install the Swar-Red theme on Ubuntu 11.10:
tar -xzvf Swar-Red.tar.gz -C ~/.themes
You can do this with Gnome Tweak Tool, or run simply this command from the Terminal:
gsettings set org.gnome.desktop.interface gtk-theme 'Swar-Red'
For more information about the theme and its developer, you can check this link.