6
You can use gtk2 themes from Gnome-Art as well.
Similar websites:
First create a .themes
folder in your home folder
mkdir ~/.themes
Download one of the themes e.g. Aero-ion which should be saved in your ~/Downloads
folder
then extract the compressed tar file into .themes
cd ~/.themes
tar -xvf ~/Downloads/GTK2-AeroIon.tar.gz
Finally Settings Manager - Appearance to apply your new theme e.g. AeroIon will appear at the top of the list.
Here is my example: