In some instances, the change in color indicates that some other breed was crossbred in at some point in the calf's lineage. i.e. Chianinas which were once tall and white with black points have somehow become shorter and black with minimal amounts of Chi in them and more Maine and Angus. The change from white to black indicated the crossbreeding of Maine and Angus into them. I guess the point I'm trying to make, MikeC, is that it's not so much important as to the quality of the calf. More towards keeping the breed purebred or identifying a calf as purebred.