I have never been a big fan of the default Brown/Orange GNOME themes that ship as standard with each new Ubuntu distribution. It turns out that there is a brilliant project called Gnome-Colours that has set itself the task of dealing with this problem.

From what I have seen from just a couple of days use, I believe that it has the potential to completely revolutionise your GNOME Desktop and make Linux a much more attractive and user friendly Operating System.

The Gnome-Colors is a project that aims to make the GNOME desktop as elegant, consistent and colorful as possible.
The current goal is to allow full color customization of themes, icons, GDM logins and splash screens. There are already six full color-schemes available; Brave (Blue), Human (Orange), Wine (Red), Noble (Purple), Wise (Green) and Dust (Chocolate).

rest here