I'm using arc-theme for Unity and I found something its github page for make it same with this:
There is a description on github page for this screenshot: "Screenshot Details: Icons: Arc | Launcher Icons based on White Pixel Icons | Wallpaper | Font: Futura Bk bt"
And I've clicked this bold text's link, a deviantart page is opened. I've downloaded white pixel icons but, it isn't like a unity icon pack. how can I use it? (I guess, it is gnome desktop in this screenshot.)