Romix is a modern flat theme with an OS X like appearance.
By: Rohith Madhavan
Based on: Numix Numix Project.
Extract the zip file to the themes directory i.e. /usr/share/themes/
To set the theme in Gnome, run the following commands in Terminal,
gsettings set org.gnome.desktop.interface gtk-theme "Romix"
gsettings set org.gnome.desktop.wm.preferences theme "Romix"
GTK+ 3.6 or above
Murrine theme engine
License: GPL-3.0+