That sounds really pretty! I would do something like a subtle natural smokey eye with really pretty silver sparkle eyeliner. I wouldn't use any purple in your makeup because that would just be too much. You want to bring out the accents in your dress, hence the silver eyeliner. (: I would use something like Urban Decays Bootycall all over your lid, Suspect in the crease, and Snakebite on the outer corners. You could wing it out a little bit, and then for the eyeliner, you could use something like Urban Decay Heavy Metal Glitter Liner in Glam Rock or if you want more of a white sparkle, you could use Urban Decay 24/7 Glide On Eye Pencil in Yeyo and go over it with Sephora Collection Glitter Liner in Opal.
Urban Decay Naked 2 Palette (Bootycall, Suspect, Snakebite)
Urban Decay Heavy Metal Liner in Glam Rock
Urban Decay Glide On Eye Pencil in Yeyo
Sephora Collection Glitter Liner in Opal
And you know what else I just thought of? You could use Make Up For Ever's Glitters in Multicolored White 3 and just use an angled eyeliner brush, wet it, and apply it on your lash line and wing it out a little bit. A little bit goes a long way (:
Make Up For Ever Glitters in Multicolored White 3
If you want to have bold eyes, I would get fake eyelashes, something like Sephora Collection False Eye Lashes in Astonish.
And for the lips I would go with something neutral like Dior Addict Lipstick in Basic 253 or Urban 178
Dior Addict Lipstick in Basic 253
Dior Addict Lipstick in Urban 178
and also go very subtle with the blush, something like Laura Mercier Second Skin Cheek Colour in Rose Petal
Laura Mercier Second Skin Cheek Colour in Rose Petal
Just some options (: lol, I hope this helps! Have fun at prom!