Thanks for all the great tips but I wasn't looking for a material that actually glowed. I meant "day-glo" as in extremely bright colors
Specifically we're trying to replicate the look of a fluorescent orange plastic whistle. In the "real world" it's even brighter than it looks in this photo:
http://www.fish4fun.com/images/Produ...valWhistle.jpg
Our orange material seems a bit muddy by comparison. How can we make the plastic bright, but not have it look like a light?