If you go in your options you can choose your Board Style in the lower right area of the screen.
You'll see a list of names.
2014M is the new, silver, metallic layout we've had most of today.
2014G is a really interesting one that I personally like a lot, so I think this one will probably end up being our primary layout.
Dark XWF should be ignored. It's the "broken" shell of what used to be our blue layout. lol
Classic Blue and White is one that looks like our old 2004-ish boards but is incomplete.
Red Blaze is a layout I think looks pretty nice and I might also fix this one up to be toggled between as you guys wish. That option has always been there and always will be there to switch your layouts.
Here is the direct link to your "edit options" screen, which you can also access through your user cp...
Let me know which layout you guys like and I'll make it my main focus as far as squashing all the bugs and restoring the rest of the features we're used to.