If you're a huge fan of Deviantart and want to make your Gnome Shell look exactly like Deviantart web site (colors and all that...) then Gnome-Shell deviantart theme is something that you'd most definitely love!.
First backup your current theme/s (default directory = /usr/share/gnome-shell/theme) and then download it from here. After the download is complete, extract the content to "/usr/share/gnome-shell/".
Now you have to restart your Gnome-Shell. To do that, press "Alt" + "F2" + "r" + "Enter", keys on your keyboard. That's it. You may also want to have a look at the original deviantart developer page as well.