Here's what you'd see on a new member one her way to Chi Omega initiation on my campus: White dress (not too finicky about it being pristine white), hair/makeup=whatever, and any shoes. But she'd be carrying white socks. What goes on past that point, well...let's just say the giant flock of owls gets released and the mayhem begins
A friend of mine in a different sorority (won't say which) was told to buy nude underwear, which seemed really weird to me at the time, but I guess it isn't that uncommon from reading this thread!