Probably not anything "racist". Who knows, he could've just been having a bad day or maybe he's just a *****......color has nothing to do with emotions or a crappy attitude!
Anyways, you're 17; you're a newbie driver. You couldn't be more likely for ANY ticket if you'd paint a target on your car or have a giant flashing billboard announcing your age. Cops look for you guys, especially men. Trust me, I went through the same crap when I was your age & so has my son. ANY deviation in the traffic laws & you're toast.
Best thing to do is exactly what you did, be respectful, lotsa 'yes sirs' & 'no sirs', keep your cool & obey to the letter any traffic laws. Time passes quicker than you think & in another couple of years you'll notice you'll start to get breaks. Whatever you do DO NOT GET A REPUTATION in the town you live in or you won't be able to turn your head without getting the heat.