Here are the rules. Make sure these rules go at the bottom of your style sheet:

.orange, a.orangelinks {
background-color: #FF9900;
}
#orange li a {
background-color: #FFCC00;
}
#orange li a:hover {
background-color: #FFFFFF;
color: #333333;
}
.green, a.greenlinks {
background-color: #66CC66;
}
#green li a {
background-color: #AEE3AE;
}
#green li a:hover {
background-color: #FFFFFF;
color: #333333;
}

The orange and green IDs are assigned to the UL tags. These modifications will not survive a modification with the PMM interface, so they need to be re-assigned after every menu edit. The time to do this task is a matter of seconds.

The orangelinks and greenlinks classes are assigned to the root level trigger <a> tags. These mods will survive a modifiy.