Quoted from o-din:I put a couple of these in there-
http://www.pinballlife.com/index.php?p=product&id=2262
I think that for $1.25 each, they are pretty cool. Good luck finding something else.
I bought one of these too, to try behind my ramp in my SOF because I couldn't decide what color would look the best. I like all the colors haha. It turns green blue red orange and purple...the purple and blue seem to add a smoke look behind my ramp. I love it!!! Here's a video about my painting my neo geo but I show my LED.