I bought 12 baby chicks at the local feed store that had been marked down to $2 because they were getting older and new babies were coming in soon. The elderly gentleman wasn't quite sure what they were, he said thought they were Buff Orpingtons. Two were a little darker than the rest when I got them, and have really gotten darker this past week or so. They don't look anything like the others, which do look like Buff Orrington when I look them up. Any idea what they could be?