Black can be any colour born, there is no discernable difference between Non Fading and Fading, but usually the greyish foals go a real deep Black when they shed and the foals born Deep Black go Grey!!! (of course there has to be a Grey parent)
It's interesting that with two tobiano parents he did not end up tobiano. Unless one or both are homozygous for tobiano, there is 25% chance of the foal being born solid...which in this case came to be