This is a pic from this morning.
So your "hens" are still young chicks? I had been assuming adults. If someone has adult hens and wants a rooster, it can make sense to get an adult rooster.
But if you have young chicks that are supposed to be all female, then I would advise not getting any rooster (adult or young) until the chicks are old enough that you can be sure they really ARE females. It's moderately common to have an accidental male in a group of females.
If you have an oops male, you could watch his behavior as he grows, and then decide whether to keep him or whether to look for a different rooster.
She's definitely got some color coming in on top of the black. I can't tell if it's gonna be blue, or maybe a silver or gray.
The one in the photo looks barred to me, with black feathers and white barring.
I do not think it is blue.
But that chick is not a female of any of the kinds in your list in the first post.
- Pure Rhode Island Reds
- Red Sex Links (Cross between RIR Rooster and Red Sex Link Hens)
- Red Rocks (Cross between RIR Rooster and Barred Rock Hens)
- Rhode Island Blue (Cross between RIR Rooster and Black Australorp)
A pure Rhode Island Red would be red, and that chick is not.
Red Sex Links would have red females and white males, and that chick is not either of those. Breeding RIR Rooster to Red Sex Link hen does not produce more Red Sex Links, but it does not produce chicks like the one in the photo either.
"Red Rock" as a cross from RIR rooster and Barred Rock hen is also called a Black Sexlink. That cross produces females that are black, and males that are black with white barring. So a male could look like the chick in the photo, but a female could not.
"Rhode Island Blue" should be blue, which that chick is not.
A cross between RIR rooster and Black Australorp would be black with no white barring, so also not right for that chick.
So you might have the wrong gender (male of the "Red Rock" aka black sexlink)
Or you might have the wrong breed (such as a Barred Rock female).
Or it could be the wrong gender and the wrong breed.