Could you help me with sexing

[mypoolgal]

I have a few chicks that I think may be Roos but not 100% sure. I attached pictures of you could help I'd appreciate it. Silkies I have no idea of sex. Frizzle I think Roo and the small brown bantam a female not sure of breed.
And breed of gray blue chicken, and brown black chicken.

 

[nuthatched]

Black is a cockerel, the two black with red spots are cockerels, they appear to be mixes except the first black and the last yellow one, which are cochins.