Active sub-menus with background color

I’m trying to recreate active sub-menus that have background color from this site:
http://www.seattlenanny.com/about-us.php

I’ve been able to recreate this in Enfold for the first level sub-menu but nothing further, as seen here:

http://test.seattlenanny.com/?page_id=24, using this CSS:

/* color of active menu item */
.header_color .main_menu ul:first-child > li.current-menu-item > a { background:#53a3b7 !important; color: #ffffff!important; }

.current-menu-item .avia-menu-text {
color: #ffffff!important;
}`

Any ideas or help would be greatly appreciated! Thanks in advance!
-Jack