Yes it is possible. I have an americauna /mix and she began laying blue eggs the first several months then molted and when she started to lay again they were lt. brown. I understood the color of the ears should tell the color of the eggs but her ears are bright blue.
The one with the brown feathers is an Americana (Easter egger) I recently bought 6 but one flew over the coop fence and was lost. One of mine just started laying and they lay blue eggs.
I have an araucana-barred rock cross bred hen that has been laying a blue egg with a darker blue center stripe. Is this unusual?
I also wanted to know why one of my RIR started laying a very abnormally shaped egg. She has been laying regular shaped eggs for the past 3 years.