Themes for GTK, gnome-shell and more.
Requirements:
- GTK 3.12
- Murrine GTK2 engine
- gtk-engines/gtk2-engines (Debian based distros also need gtk2-pixbuf-engine.)
Fedora/RedHat distros: yum install gtk-murrine-engine gtk2-engines
Ubuntu/Mint/Debian distros: sudo apt-get install gtk2-engines-murrine gtk2-engines-pixbuf
ArchLinux: pacman -S gtk-engine-murrine gtk-engines
Other: Search for the engines in your distribution's repository or install the engines from source.