My bieles lay less often than my BCMs but many have eggs almost as dark as my lightest marans. Most of my marans are much darker, but the Bieles do have a fairly large color swing from light to dark brown. They are a heavier bird and do break more eggs with their heavy bodies though which is annoying. I am working on a roll out nest box to hep solve this. Bieles are more gentle tempered, if a bit dull witted I find that the marans eat more really, but they are also a lot more active and also produce xl to jumbo for me almost daily In the pic below are all marans and bielefelder eggs.