Hopefully someone else can give you direction. I simply don't know. You may want to see if there is any help on this forum as well:I need a little help. I'm trying to breed to the standard but I'm down to one rooster I lost my other one and this one all of a sudden grew two white tail feathers. Is it possible to breed this out in future birds?
https://www.backyardchickens.com/f/16188/exhibition-genetics-breeding-to-the-standard-of-perfection