Twitter Bootstrap: multiple modal on same page, want different background colors

[ThatDudeBrad]

I have 2 modals on a page, see: http://twitter.github.com/bootstrap/javascript.html#modals. I want them to have different page background colors. The JS seems to generate \[code\]<div class="modal-backdrop fade in"></div>\[/code\] at the bottom of the page. Is there a way to set a class or something to it via Bootstrap config?