I got an email alert from Missouri Quilt Co this morning. They have something called Bella Solids Porcelain on their daily deal. To me, it looks like it has a little sheen. BTW the deal is 2 yards for $6.
Michael Miller's Fairy Frost is also a good choice.
Northcott has a couple of lines. Sorry don't know the names but one is white with white swirls and the other is white with heavier white like a blender.
You could also quilt it using a silvery thread to emphasize the stormtrooper .