Creating an attractive GUI is not easy – what I thinks is attractive might be regarded as horrible by someone else., being a relatively young completely web-based application, allowed GUI changes from early on.
Navigation menu bar, buttons, banners, text colors – all of this can be changed to meet your (corporate) requirements.
Even CSS themes are supported.

No clue what this is all about?

Then you should definitely check out the following Wiki article:

CSS Themes

To take UI design to an even higher level is working on a CM (Content Management) plugin.

Now this plugin will provide unparalleled UI design! As a scoop – click on the picture below…. btw: I don’t know (yet) when this plugin will be available…..

CMS Screenshot