Yes there have been others whom have posted photos of these deer on this site. The black deer that you refer to is called I think a Melanistic Deer, it is kindof like the opposite of an albino. A albino has a total lack of pigmentation, whereas a Melanistic Deer has an over obundance, total saturation of pigment. Your are lucky to have seen it, I have never had the pleasure of seeing one in person, just photos.