Ya really gotta 'catch them in the act' to know for sure. I've never had Orps.
Thank you for your help, I am happy that I finally got brown eggs and I'll be watching them during the week to find out who is laying which ones.
That's what I did, I'd watch to see when anyone goes or in the NB then would run out to see who was sitting where. Kept checking, did this for several days until I was sure.
@aart I love Orps personality plus their puffiness.