The theme generally uses dark colors for the window title and the menus, combined with an orange contrast for selections etc. There are no roundings and such polishing as they would be against the design philosophy of this theme.
The icons are from the Numix icon set which is not yet available…
Numix also includes a GTK 2.0 theme using Murrine engine, that will provide the essential optical consistency when using applications that are yet to make the leap to GTK3.
Satya is proving once again that he is a talented creator with this minimalistic, brilliant looking theme. You should give it a try and see how it feels on your eyes.