finnfur
Songster
I'm by know way an expert but I would only go 70% its a cockerel - I've got some slow [not size] developers at 7 weeks that could still go either way.
You really can't be certain of coloration until first molt IMHO . I just weighed some at 5 weeks for a comparison if you want to weigh it.
14 Birds - Largest 14 Oz - smallest [Runt] 8.2 Oz and average was 11.57 oz [These are my Blue line from Kathys line.]