Three weeks is young. I would think autosomal red leakage could be what's going on if they continue to come in red in the male pattern areas. One feather wouldn't keep me awake nights unless I wanted to breed breeding quality Splash from this chick someday. Red in the shoulders and chest would be worrisome. The chick is a long ways off from knowing if it's just one red wing feather or if when the chick is an adult and after molting, the red wing feather grows back in. The Splash chick would then have a DQ and make it pet quality. Not an issue if the chick is never destined for the show bench. Autosomal red is very difficult to breed out of a pen once it gets established.
Thanks!I am pretty sure the brahma that hatched at the same time is a cockerel and already have one in my flock. I'll just wait and see!