The head coloring is harder than the back. You'll get some white in front of the eyes and under the bill that should be culled for. Also you don't want the gray going down the neck to far as well. You'll get some going down to far if you don't cull for it. Especially down the back of the neck.
Leg banding is a very good idea to keep track of individuals. I personally band every bird on my place. I band one leg with a colored zip tie that indicates what year they were born in and a red or blue tie indicating sex. And the other leg with a numbered leg band and a combination of colored zip ties that indicate where that bird came from ,as in what other breeder. Right it all down too, you'll think you can remember but after a couple years you'll forget. Or at least I do.
