You can mix those girl's with a Naked Neck rooster and end up with even more colors that the pullet offspring will lay. I did that. I had a few that would lay green egg's, but I used the Crested Cream Legbar's.I was surprised how many eggs mine lays. She's still young, but I don't think she's missed a day yet.
If I weren't so keen on getting some colored eggs, I'd probably get more NNs. Right now I have an order for EEs, OEs, and Legbars.