Oh, poop. Sorry I missed that thread. I'll post it over there, too.
I like your take on it, but actually I'm supposed to be a "Devil With a Blue Dress On" (like the song).
I saw a really cool one last night - another girl came as half devil, half angel, cut right down the middle. Even painted half her face all red and had fire-engine red hair on that side and platinum blonde on the other (she used a rinse on her own hair, which is platinum blonde. Hope it comes out OK!)
I actually already had the dress and shoes - I bought them the same day many years ago to wear to a semi-formal New Year's Eve party. Never wore either since, so they are in mint condition. I just had to buy the wig with horns and pitch fork, which I found at my friendly neighborhood Target.