look in her mouth and see if she has canker. it's a yellow cheese looking stuff. it will make them breath funny and not eat right. here is a page about Poultry diseases. you might have alook and see something.
i have rir bread by a lt brown leghorn crosses. and they scratch the yard and woods up looking for stuff. don't know about how they are laying because they are only 4 months old and not laying yet. not even my old hens are laying right now. but good luck.
most of them will bee white with leaking color. the white is dominate. i only got one hen left. she is about 6 months old her pop was white leghorn and mom was black asutralop. she is white with grey leaking trough.