That's doesn't quite look like a blue shell inside,I know this thread is old. I was making deviled eggs yesterday and I noticed all my brown eggs had a white inside. The green and blue ones had a blue inside. However my dark brown eggs had a blue inside. The picture below is just from a fresh one with a little bit of the membrane removed to show the blue. Does this mean she would lay green eggs if the brown coating wasn't so dark?
just some staining or shadows on the white membrane.
Need to pull the membrane out to see the shell color clearly.