I'd implore you to take a look at a gallery of sites built with bootstrap: http://builtwithbootstrap.com.

I think you'll be pleasantly surprised to find that not all sites built with Bootstrap follow the default mold of a thin 100%-width black navigation bar across the top with white background. Sure, there are lots that have that layout, but as developers learn more about Bootstrap, the sites that use it as their underlying framework are definitely diversifying.