Wheel color, brand, and style suggestions for my 1970 dart?

What would look best on a car can vary person to person. What do you want out of a wheel and tire combo. If you want to pursue the handling route, you need a wheel that's at least 17" in diameter. If you're fine with just cruising or prefer an older look there are a wide variety of of 15" wheels. You want drag racing... well, I don't know drag racing so you can ask them folks.