Windows 7 - How to apply aero to the Roboform toolbar

I have a stylish css script that does a great job of making Firefox look great. The only part that I can't seem to get to go transparent is my roboform toolbar. I have successfully figured out how to change its color but if I try to make it transparent, it shows as black. Anyone have any ideas? Here is the section of my css script that changes the color of the roboform toolbar:

#roboform-bar {
background: blue !important;
min-height: 24px !important;
}