Every once in awhile someone will have a standard baby that is brown at birth. I overheard a rancher at a show call them "Cinnamon Babies". When I asked about it, he mentioned that he had tried breeding for it, but it always dissappears by six months of age.
As far as I can tell, there is no difference in an adult chin that was born a normal standard color and one that was born this brown color. They all end up nice blue-grey in the end.