Does the guy in blue think the baby is going to come out dead?

Weird gimmick.

I mean that other lady is wearing white. I assume she's the pregnant lady and she didn't even follow her own rule.

me showing up in my purple Prince suit

"I hope the one eyed, one horned, flying purple people eater doesn't show up."

Was she right?

Ok, sure, she did not read the instructions. But what is the problem of guessing black? Obviously, if they are asking you to guess, that must mean there is some level of uncertainty regarding the child's colour. Humans do not come in many different shades but black is surely one of them. It would have been really weird, for instance, if someone were to guess blue

Well at least she wasn't wearing blue or green.