What are these gals?

Hello! I just got my first set of 6 chicks a couple of days ago. They are such little sweeties! I have two buff orpingtons, two barred rock pullets, and then there are two that I am not quite sure what they are! They are solid black with a little bit of brown on the wings. I don't have the best pictures, but I have one that shows the brown on the wing, the bird from the side, and one that's a clear shot of the face and beak. 

The two on the far left are the two I'm trying to identify. See the little bit of brown on the wings?:

Here's a shot of the face. The little gal peeking out in the middle of the two Buff orpingtons is one of the ones I'm trying to identify, and she is such a character! She's one of my favorites.

Okay, thank you! From a google search, I see that sexlink male chicks look a lot like my barred rock female chicks, in the center right of the first picture. Hmmm...I hope I wasn't accidentally given two roosters! 

Edit to clarify: The ones I'm trying to identify are the two chicks on the right in the first picture, without the white spots, and in the second picture, the black one poking her head up is one of the two chicks I'm trying to identify. 

thank you! I got these from TSC, actually my husband did, and he was told the chicks are 'a few days old.' Is there any way to tell a little more accurately how old they are? They have to be less than a week old, but I'm guessing in another week or so it will be more obvious how old they are.