May 22, 2014, 12:17 PM — Zukitwo Dark GNOME Shell theme offers a pleasing alternative look to your desktop. Here's how you can install it in Ubuntu 14.04.
1. Open a terminal window.
2. Type in the following commands then hit Enter after each.
sudo add-apt-repository ppa:noobslab/themes
sudo apt-get update
sudo apt-get install zukitwo-dark-shell
According to Noobs Lab:
Zukitwo dark themes for Gnome Shell and Cinnamon is designed by zagortenay333, there is other Zutikwo GTK and Gnome Shell themes available but these are different from them. Both versions look elegant dark colors with white lining. Gnome shell version is compatible with 3.12 but it can also work with 3.10. For Gnome shell you can use Gnome Tweak tool to change shell themes (Don't forget to install Gnome shell extensions and enable user themes).
Image credit: Noobs Lab