thats a dumb rule, so if your a customer and your about to buy a mono or damier bag and a non matching accessory to go with what ever bag you get, they will tell u no! uhhh they would lose a sale from me lol!
LOL If my SA told me that I'd ask her when she was going to order and pay for all of the accessories that should go with my bags. All of my accessories are Mono so far and I put them in all of my bags regardless of which it is cause I don't currently have a choice. LOL What I lvoe is that I can fit the same things in my Damier Ribera MM that I can in my Mono Stephen...albiet I have to arrange neatly in the Ribera.