Black sex-links will be black. And most black feathers have that green sheen, my BR's black bars have the green sheen. I think Black sex-link males have color leakage on the hackles and wings, but I could be wrong. I don't have them.
I have two black sex links and they're mostly black with the green sheen. They also have have gold near the neck and throat area. It's really not obvious until they move a certain way and the gold peeks through but it's definitely there.
Edited to add: The body type is different, too. At least different from my two.