OK, was going to put this in the bugs forum, but it isn't really a bug with the C2 Engine, but just a glitch in the Styles for the Editor, hence no capx.
Just wanted to let Ashley know that Office 2013 styles do not retain the style for the tabs.
This is how the tabs appear when the style is loaded using View\Themes\Style options:
This is how the tabs appear when you restart C2:
So you have to reselect the style every time you start C2 so that the Tabs are consistent with the style.
And on a side note the status bar is always Blue, it would be nice if it would match the selected style. The Office 2013 Dark Grey style should be dark grey for example.
Just a minor thing but would love to see it fixed.