BuddyPress.org

I found the property using Firebug on Firefox:

.wp-caption, ol.commentlist li, #cf {

-moz-background-clip:border !important;

-moz-background-inline-policy:continuous !important;

-moz-background-origin:padding !important;

background:#FFFFFF none repeat scroll 0 0 !important;

}

Change the background property and you’re done.

But it looks that the CSS propoerty is part of your templates options. So check the template options or the file theme-options.php

Hope this will help.