|Zuki with Gnome desktop|
To be honest, the colors are "inspired" by MacOSX it seems, but the rest assured, it looks clean and elegant. There is a GTK theme engine called Murrine, and the Zuki is based on that engine. The theme support both Nautilus and the Nautilus elementary. If you want to use the simplified elementary version, then you'll have to install it first. But you can still you the theme with the default Nautilus as well.
*. First download the zipped package from here.
*. Now, extract the content to "/home/Your Username/.themes" or if you want the theme to be available for all the users, then extract the content to "/usr/share/themes" (you'll need administrator privileges for that).