Bellissim developed for GTK-themes Arc and at first glance looks pretty good. The downside is that the icon set was created more recently and covers only a small number of applications, including GIMP, Nautilus and Gedit. It is inherited from Ubuntu Mono Dark icons on top panel are painted in bright colors, and most of the icons of the applications (Firefox, Geary, Corebird and so on) use their standard icon or option.
Installation latest version into Linux Mint:
2. Unpack to ~/.icons in your Home folder
3. Enable icons in theme options