Sphere icon theme is complete and well designed for Linux. Last version 1.2.5 released in 2013 and got many improvements. We added blue places in our PPA, if you want to try other colors (Dust, Orange, Red, Green, Petrol and Violet) then scroll to see the commands for that colors, first of all install icons then change color of places if you want to change any. Sphere icons offer more than 8000 icons from 16x16 to 255x255 sizes. The development of this icon set is stopped, so do not expect any update for missing icon. You can use Unity Tweak Tool, Gnome-tweak-tool or Ubuntu-Tweak to change icons.
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