Bootstrap transparent navbar

I just figured it out. For anyone who needs this in the future. I added a CSS override that was:

.navbar.transparent.navbar-inverse .navbar-inner {
   background: rgba(0,0,0,0.4);
}

And my html syntax looks like:

<div class="navbar transparent navbar-inverse navbar-fixed-top">
   <nav class="navbar-inner">
   ...
   </div>
</div>