Square-Beam icon theme is redesigned and developed by the same guy who release
Square icons for Linux (Eep Setiawan), it is based on Faenza, NITRUX, Moka, and Pacifica icon sets. This icon theme is elegant offers wide variety of icons, which contains more than 30,000 different icons. It can work on any theme whether light or dark. You can use
Unity Tweak Tool,
Gnome-tweak-tool or
Ubuntu-Tweak to change themes/icons.
Screenshots
To install Square Beam icon theme in Ubuntu 15.04/14.10/14.04/12.04/Linux Mint 17.1/17/13 open Terminal (Press Ctrl+Alt+T) and copy the following commands in the Terminal:
That's it