All icons are available for use under a Creative Commons ShareAlike license.
Flat remix is a pretty simple icon theme, derived from Ultra-Flat-Icons, Paper, EvoPop and Numix-Circle icon themes. Its design is mostly flat with a subtle use of shadows, highlights and gradients for some depth.
It has been designed specially in gnome shell 3.22 but it should work with most linux distributions, under gnome, unity, cinammon, xfce, kde, etc.
This theme was made to fit with the Flat Remix GNOME theme.
If you want to install it manually:
Download and uncompress the zip file.
Move "Flat Remix" folder to ".icons" in your home directory.
Select "Flat Remix" as icon theme in your tweak tools application.
If you prefer to use the terminal:
cd /tmp
git clone https://github.com/daniruiz/Flat-Remix
mkdir -p ~/.icons
mv "Flat-Remix/Flat Remix" ~/.icons
You can also support the development of Flat Remix by donating. And I'll give you some candies :)