This is a pen & ink drawing that has been (amateurishly) stained in Painter 8! I haven't worked much with Painter, I bought it a few years ago and it ran so slowly on my old computer that it was useless. Now, it's slightly useable, but at a much lower resolution than I prefer to work at.
I do like what it can do-- maybe I'll start messing around with it and see if I can get some more use out of it.
...These guys are Frank and Jesse James, referenced from a book on the Old West. Here's the original drawing without the color experiment: