Polar Night (Dark) Gtk Theme for Ubuntu 14.04 Trusty Tahr

Polar Night theme is a dark variant of flatts theme, it is specially customized to work under Ubuntu 14.04 Trusty with Unity and Gnome Desktop. This includes theme for Gtk2, Gtk3, Metacity and Unity, this theme contains a workaround to get rid of a bug that clashes with overlay scrollbars and draws black backgrounds in tabbed Nautilus and Gedit windows, and in some Ubuntu dialogues
Nautilus specific changes, to buttons, linked buttons; Unity window decorations changes. You can use Unity Tweak Tool, Gnome-tweak-tool or Ubuntu-Tweak to change themes/icons. Ardis icons used in screenshots.

>> Available for Ubuntu 14.04 Trusty Tahr
To install Polar Night GTK theme in Ubuntu/Linux Mint open Terminal (Press Ctrl+Alt+T) and copy the following commands in the Terminal:

Terminal Commands:
sudo add-apt-repository ppa:noobslab/themes
sudo apt-get update
sudo apt-get install polar-night-gtk

Dorian Theme offers theme for software center because with dark theme text isn't visible in the software center enter these commands in terminal to fix software center issue:

Terminal Commands:
cd /usr/share/software-center/ui/gtk3/css/ && sudo mv softwarecenter.css softwarecenter.css.backup
cd /usr/share/software-center/ui/gtk3/art/ && sudo mv stipple.png stipple.png.backup
cd && wget -O softwarecenter.css http://drive.noobslab.com/data/themes/dorian/softwarecenter.css
sudo mv softwarecenter.css /usr/share/software-center/ui/gtk3/css/
cd && wget -O stipple.png http://drive.noobslab.com/data/themes/dorian/stipple.png
sudo mv stipple.png /usr/share/software-center/ui/gtk3/art/

To revert back software center theme to previous state simply enter these commands:

Terminal Commands:
cd /usr/share/software-center/ui/gtk3/css/ && sudo mv softwarecenter.css.backup softwarecenter.css
cd /usr/share/software-center/ui/gtk3/art/ && sudo mv stipple.png.backup stipple.png

That's it