@Chazrox looks cool! I want to customize mine. How do you do it?
if you want to make it more stylish and not so flat, here is a workaround. Turn the transparency down on the grey for example. Put it at zero. Then add a custom image and use it as the background for the browser. You can create an image in photoshop. If you don't have photoshop let me know I can help you make something that looks good.
The way I do it is create a panel, then add the image to that panel with the browser preset window, all of them the same size to fit into the panel. I set both the transparency on the Panel and the browser background to zero. Then the custom image will show through.