I'm quite sure he won't be wearing black leather(in the jungle?!!
). He was just using that as an example of how you have to make certain accomodations when translating some elements from comic page to the screen. He already clearly stated that The Phantom is not like Batman or The Punisher. There is a certain darkness to the concept but not to the extent of the latter two.
Regarding as to what color The Phantom's costume will be, I wouldn't be surprised if it ends up being more greyish rather than purple. Heck, I wouldn't mind if he wears a dark blue suit like in the Scandinavian comics.