What is this? Help me ID :)

[Chick-Norris]

We ordered 5 red sex link pullets, and picked them up two weeks ago. 4 look pretty similar, and one looks *really* different. She's beautiful, but so much darker than the others. Wondering if there was a mix up?
Thanks!

 

[Rhodebar Lover]

Production Red, looks like a cockerel already too

 

[Chick-Norris]

Production Red, looks like a cockerel already too

Eek, really? How can you tell? Thanks for the quick reply!

 

[Rhodebar Lover]

The comb is very large for such a young chick