Status: Retired (sorta)
BrickLink: Glitter Trans-Clear (not a perfect match, of course)
Lego calls this part just 40 Transparent, but it has a very unique coating/glitter additive. It's hard to describe, since it looks so different from various angles.
It's alternately glitter-gold and milky greenish from the front, and a sort of milky white from the back.