I dont know if its mentioned in the movie or in the dvd’s special features, but the black suites are explained.
[quote]Well, typically during a robbery people panic…can u imagine being caught in a robbery as an employee or a customer…and these 6 gangsters bust out guns…it’d be hard to remember what they look like cause they are all wearing the same thing. Most you could remember is, "One had a mustache, one was older…one had yeah you get the picture.
[/quote]
Thats basically how it was explained when I heard it.