Custom Backgrounds on Bubble Chat?

The main question is this possible and how might I go about it.

I have an idea that will give a better feel to my game, making the Background of bubble chat black to go with my overall theme, black. Is there a way to do this on ROBLOX?

Note: I'm not asking for a script, I'm just asking for ways I might go about this or if it is even possible, to begin with.

Thanks, DrBaja

http://wiki.roblox.com/index.php?title=Chat#Bubble

Go into Roblox Studio, hit "F5"

Take a look in your Explorer window for the Chat service

Inside of Chat service you'll see BubbleChat

Copy BubbleChat, hit "Shift+F5", paste into your empty Chat service.

You've made a copy of BubbleChat! Now explore the script and make your changes.