You guys may already know about Ravefinity and their contribution to themes/icons. In past there was theme and icon suite called Bisigi, it was awesome project but not maintained anymore I was quite disappointed because the Bisigi project was not maintained anymore and nobody was willing to continue this project, but Bisigi is still compatible with one desktop called "MATE" because Mate is based on Gnome 2 and this project is designed for Gnome 2. I am trying to say Linux is great operating system, if somebody leaves others come and fill up the empty space, like many other great artists Ravefinity is doing great work by contributing his work on themes and icons, we wish them best of luck for future work.
Vibrantly-simple icon suite is just updated by Ravefinity and is now compatible with all current Ubuntu/Linux Mint versions and upcoming Ubuntu 15.04 version. It offers icons in 14 colors with light and dark panel support which means you can use it with any light or dark theme, and it contains more than 31,000+ icons for all colors. It is compatible with most of the Linux desktop environments such as Unity, Gnome, KDE, Cinnamon, Mate, Lxde, and others. For this icon theme most of the application icons available, still if you found any missing icon or bug in this set then report it. Radiance colors, and Ambiance-blackout-colors themes used in following screenshots. You can use Unity Tweak Tool, Gnome-tweak-tool or Ubuntu-Tweak to change themes/icons.
>> Available for Ubuntu 15.04 Vivid/14.10 Utopic/14.04 Trusty/12.04 Precise/Linux Mint 17.1/17/13/and other Ubuntu derivatives
To install Vibrantly-Simple icons in Ubuntu/Linux Mint via PPA open Terminal (Press Ctrl+Alt+T) and copy the following commands in the Terminal: