Trouble setting Accordion to be opaque

Trouble setting Accordion to be opaque

For some reason, the background color of the jQuery UI Accordion seems to be transparent. This is a bit of an issue because some of accordions expand over existing fixed content, but I'm having some trouble setting it to opaque with the usual suspects.
  1. background-color: white;
    opacity: 1;
    z-index: 0;

I've tried setting these in both the CSS .ui-accordion .ui-accordion-content as well as directly in the HTML.

Any suggestions?