I totally agree with you that the eggs in Rome are much more orange and the yolks much more flavorful than in the States. I've bought organic eggs in NY and SF and none of them have that dark orange yolk. I'm guessing it's the feed but maybe even the breed? Anyways, that's probably the main factor in not being able to re-create carbonara. We can get decent cheese, pasta, and guanciale but those darned eggs.