I would have to agree with everyone. Confused? Well a hen's legs can fade during egg production or due to age, but I personally have not seen yellow fade to white with dark spots. I have seen yellow fade to white with no spots of off colored yellow spots that can fade even more. She does look to have a Cuckoo color pattern, but that too could be a color or aging flaw. From what I understand if she is a Maran she should lay dark chocolate colored eggs in the beginning of her laying cycle that can lighten up to just brown eggs as her laying goes on. But note that from my researching some Marans do not ever lay dark chocolate eggs and would be disqualified in show. So she could be pure or crossed, but I do not think she pure BR.
