Fair enough, typical Chocolate markers I am aware of are often granite like side patterns, no / low black, little yellows, just browns. The problem is he just doesn't look much like many other chocolates either. It is subtle but he is quite dark but not black just brown. I think it is a fairly common naturally occurring phase, of course so are mojave. To my eye he isn't quite normal either just different, I think from my understanding chocolate fits.

"Chocolate balls are one of the nicest mutations available. They are a blushed brown with floating aliens and a dark mottled belly."
John Berry