In fact, translucent plastic is used an awful lot in the other toys too. Actually when you think about it, Hasbro has been quite big on the translucent plastic lately. It's become quite the rage, apparently. Click for detail. And when you think about it, that's probably what it is.
Translucent stuff is big just about everywhere.
Our computers have it. Our toys have it. Our shelf organizers have it. Our pencil boxes have it. Hell, I've even seen iMac-esque TVs, for crying out loud.