Install Sphere icon theme in Ubuntu 12.10
How to add the Sphere icons in Ubuntu 12.10
Here's how you can install the Sphere icon them in Ubuntu 12.10.
1. Open a terminal window.
2. Type in the following commands then hit Enter after each.
sudo apt-get install sphere-icons
gsettings set org.gnome.desktop.interface icon-theme 'Sphere 1.2'
For more, see the original article at the link below.