Pink - comb genetics are weird. There are actually more tinted/pinkish laying peacombed birds than blue laying peacombed birds. Asils, Malays, Brahmas, Buckeyes, Cornish, Sumatras, Shamos... and what about silkies that have the walnut comb? They usually carry the PP peacomb gene with the RR rosecomb to give them the walnut comb. I know there are some blue laying silkies out there, but it's not the norm.
I think that the blue egg color segregrates away from the peacomb easier than the other way around (single combed rarely lay blue, but peacombs often lay non-blue). Maybe it's because Aseel, Brahma, Cornish and Sumatra are relatively old breeds and went into the formation of many of the common breeds we have today. And from the beginning they carried the Peacomb/non-blue laying combination so it's passed on to a disproportionate number of the chicken breeds we know today. The peacomb mutation probably happened separately in the East (India, Indonesia, China) and in the South - South America. I don't think anyone knows what came first the peacomb or the blue egg. But only in South America they ended up together.
I've read about single combed blue egg laying leghorns, so there must be different ways the genes can be "parked".
You're right though, for any Araucana/Ameraucana based EE's the peacomb is a great indicator. Sorry this is probably more for the EE thread than the Marans!
Separate question: Those who live in the frigid North! Is a split egg a good indicator of a frozen egg or can they be frozen without cracking? Frozen eggs go back to the chickens or to the dogs, some seem awfully cold, but I only pull the split open ones.