Violet is a solid black and even though she is a puppy farm ex-breeding bitch, you couldn't wish for a more soppy, laid back dog than her. I've only had her for 5 months and she has never shown any aggression whatsoever to anyone.
From talking to other people when out walking etc and friends with black cockers, I'm coming to the conclusion that black cockers have a bit of a reputation for being very good natured, laid back little dogs.