I am not an expert on this issue but much of the black on the front ought to be brown, the colors don't pop, and most importantly, the exact image on this card, stains, dirt and all, is on a card in the Library of Congress.
http://www.ebay.com/itm/251809114096...%3AMEBIDX%3AIT
http://www.loc.gov/item/2007680746/