I got a grey egg yesterday from my olive egger! At least in th edit light of the barn it looked grey. I was so excited. When I rubbed it the bloom came off and it looked olive. Today, if she lays again, I will not rub off the bloom, and post a photo.
Her daughter is 4/5 years old. (one left) I still have hope, the gray hen had the daughter at 6 years. I have not hatched any of her eggs. Below is one of them to look at...Dark gray.