There is probably a better place to ask this question, but I couldn't figure out how.
It usually works better to start a new thread, in the same forum. That helps avoid confusion when people give an answer that could apply to either question
In a similar vein, is it possible that my Polish crested is laying blue eggs?
A Polish cannot lay blue eggs.
Most chickens that lay blue eggs do not look like Polish.
But there's always a chance that you could have a chicken that lays blue eggs and does look like a Polish. Some hatcheries have been crossing breeds to produce blue egg layers with a variety of appearances.
In my flock of 16, there are two easter eggers giving me green eggs, two Ameraucana laying blue , and every one else from an assortment of breeds is laying eggs that are light pink to dark brown. I have been getting two blue eggs every day for weeks, and today I got three.
Sometimes a hen that normally lays brown eggs will lay a very pale egg, or even a white egg. It's as if she skips the final step (the brown coating on the outside.)
A green egg is a blue egg with a brown coating on it. Maybe one of your green eggers laid an egg without the brown coating, so it looked blue? (Unless you also got 2 green eggs that day.)
Or maybe one of your other chickens is an Easter Egger in disguise, and just now started to lay.
I have never seen my Crested in the nesting box, and I just thought she was never going to lay, because I have never had a white egg.
I think Polish sometimes lay pale eggs that are not properly white-- so she might be laying eggs that are not really white, or she might not be laying yet.
Can you post a picture? Some breeds look similar to each other but lay different colors of eggs, so one of us might be able to figure out if she's really Polish or is actually some other breed that looks similar.