My cat Tux had just gotten out on Halloween night, he ran out the door when the trick or treaters were here. After an hour I went out back and called him and he came running back. Was very happy to see he was safe. He's mostly a black cat too.
Spamlet, I live in America too, and many Humane societys have a rule stating that no black cats are eligable for adoption during the month of October, there are sick people out there that will find black cats or whatnot for Halloween and torture/kill them.