i had exactly the same thought when i had completed it. Thats a little bit above my head, but certainly more than possible.

I would most likely split it into three main backround images

"viewer"
"controls"
"puck"

then just change the background images, to acheive your desired look.

Alternatively what i can do is create the design as custom ui objects, and then allow you the user to change the colour from within the application.

Update and New release
 

I'm still here, just busy enjoying uni life. 0.8.0.1 is ready, the the ui has been completely rewritten, the graphics haven't been added yet, but its a formality.
Plus the even bigger news is, i started working on some apps written in plain old C++. So hopefully i can get one of those to market soon.

Things will really speed up once i get my paws on my Black macbook core2duo, so i can work in my boring lectures. ^_^

Anyways by the time you read this version 0.8.0.1 should be in the freeware section, so check it out.