The installation can be done with the help of a PPA
Nitrux OS Icons, a pack of handcrafted icons that are compatible with a lot of operating systems, including Ubuntu 13.04, has been updated to version 3.1.1.The icons in Nitrux OS are infinitely scalable, which means that they are compatible with a large number of operating systems.
With over 6000 icon available, it's hard to find a program that doesn't get it's own personalized icon. According to the developer, a number of icons have been revised in this version and a small number of fixes have been implemented.
The Chrome, Chromium, Redshift, Ktorrent, Epiphany, Deluge, and the Volume indicator are just a few of the icons that have been remade.
The installation for Ubuntu 13.04 is quite simple and it can be done from a terminal:
sudo add-apt-repository ppa:upubuntu-com/nitrux
sudo apt-get update
sudo apt-get install nitruxos
You can also download Nitrux OS Icons 3.1.1 right now from Softpedia.