Hmm I did talk to tim about this and I think you are right about the blue stopping the leakage in the hackle ... I will give that a try ... I have cocoapop in the 12 oz and I will continue to breed them down to about 6 or 7 for hens and 9 to 10 oz for rooster...
You can also stop leakage from mate to a pure black with black legs that always stop the leakage ... Only thing is when you try to breed for that yellow legs the leakage come back ...