We have previously covered many icon themes for Ubuntu, you can check them here. Today we will see another icon theme for Ubuntu called Hydroxygen, which we will help you install and enable under Ubuntu 11.10/12.04. Here are icons used by Hydroxygen:
Hydroxygen Icon Theme Installation
You can download and install this icon theme manually from this link, or run simply this sequence of commands from the terminal to install and enable hydroxygen:
cd /tmp && wget -O hydroxygen.zip http://goo.gl/bYAay
unzip hydroxygen.zip && cd iconset
sudo tar jxvf hydroxygen_iconset.tar.bz2 -C /usr/share/icons/
gsettings set org.gnome.desktop.interface icon-theme 'hydroxygen'
Here are some screenshots for hydroxygen under Ubuntu Oneiric: