pardon me, I'm sure they are technically coated, but it is certainly not a thick coating that easy to mar, as with the super-smeary marans.
Yes, that is true. Sorry to not have made that clear.
The darker the egg the easier it is to smear it. I have had Production Reds, Penedesenca and a couple of other dark egg layers lay eggs that lost the brown--especially when boiling them.
Bresse are white shell layers with a coating. Look at your own eggs--if they are tinted they have a brown coating.