Custom CSS Class

Hi all,

I want to give my premium members a special background image. How would I go about making BuddyPress give each user a custom CSS class on their profile page based upon their user role?

What I mean by that is that I can set a background color on all profile pages with something like:
body.bp-user {
background: #ccc;
}

But what I would like is to have a code that gives each user a custom class based on their role, so I could use a code such as:
body.s2-level-1

Or:
body.subscriber (WP default)