Coolantcould leak in there but you would more than likely have a milkshake mix in the tranny and it would be like a pinkish sludge. If the black was on the stick, that's fairly normal if you haven't checked it in a while. If the fluid was more of a brownish red or whatever it's probably burnt, you should also be able to tell if its burnt from the smell. Get a white napkin or something and drip a little fluid on it from the stick to see it's true color. Since you have never checked it in over a year I'm guessing your not a DIY type of guy so easiest way would be to just go have a flush done. They will flush out all old, add new and hopefully to the correct level. If theres a reputable transmission shop it wouldn't hurt to run it by there and see what they say but most places will just try and sell you a rebuild. But my guess would be the idiots at the dealer didn't do their job and you been driving like that since you got it...