What I found very interesting about the colour 'myths' is that when we were looking at pups and knew nothing at all - breeders of blue roans told us solids were agressive, possessive and not good with people, while breeders of solids said that particolours were scatty, neurotic and not very bright
These were not just one off comments, but seemd to be genuine beliefs of a number of different people we talked too, including a vet
This was 7 years ago - so hopefully ideas have changed a little since then