So, you mean you want to create a Dun/Chocolate Ameraucana? (or khaki, or platinum, etc)
An easy route is getting some of Jean's stock, really. My buff hen was once hers, and she's the one who often mentioned the fact that she had darks, lights, and some occasional black/browns.
And if you're into making dun/platinum/khaki Am's, cross out to black and keep doing it but with dun carrying birds. Get rid of all the color leakage you can.

An easy route is getting some of Jean's stock, really. My buff hen was once hers, and she's the one who often mentioned the fact that she had darks, lights, and some occasional black/browns.
And if you're into making dun/platinum/khaki Am's, cross out to black and keep doing it but with dun carrying birds. Get rid of all the color leakage you can.