Not even sure bread or gender
I think your loaf is a mixed breed. :) Although it could be a black sexlink rooster (sexlinks are a mix of breeds). I'm pretty sure it's a rooster.
Dixie rainbow makes sense, and would also explain why he's grown so fast. :)
A red sex link pullet will be red on the front and white at the tail. Have any like that?
Maybe it is a pumpernickel. LOL
I don't have hardly any experience with these guys, and there is a lot of variation with sex links because they can be mixes of different breeds. Normally I'd suspect the chipmunk chick on the left as your sexlink, but I assume that's the chick that turned into your dixie rainbow/pumpernickel. :) I'm going to guess that the red sex link is one of the two that are just a bit more shaded and a bit more reddish - on the top and the far right. What did those two grow up to be?
Edit - just read your post more carefully. Yes, the chicken on the left is likely your sex link. :)
Edited by MonicainAZ - 4/21/16 at 3:05pm