I'm afraid I have some bad news. While they both appear to be young roos, they are not marans. Cuckoo marans have white legs, not yellow, like these birds do. Unfortunately, this is all too common in hatchery birds since they often cross them with barred rocks out of ignorance and greed. If you are seriously wanting good stock and good egg color my suggestion would be to keep neither. I am not trying to be harsh, I just want to let you know before you get too far into it. If it were me, I would also contact the source to let them know that what they are selling is not a marans. It really frustrates me when I see people get taken advantage of with this breed.
Richard