Well, firstly - The reason people get Wheatens from BCMs is that BCMs were made from Wheaten. Second - If it is a hen, it's your choice to keep it or not. Some people keep theirs, and just keep them seperate from any breeding. Personally I'm curious what I will do if I get one from my current eggs. As 5 of them are already supposed to be Wheaten, and both BCs and Wheatens in my bator are Bev Davis, I wonder if it is safe to introduce the fluke Wheatie to the expected Wheaties.
Anyway, about that - I'm really not sure. I know the color will turn out a little different if you cross the two, as you should get more Wheaties, but the egg color I'm not sure on. Should be the same, since it is the same bloodlines? As for it being a roo over the BCMs, I personally wouldn't do that. If it were a pullet, I'd keep it and see how it lays. You could also cull or sell it though.