Plugs should never be black. Period. Never. I drive around town all the time. My car is my daily driver any day it can be. In fact I just drove about 10km at speeds under 60kmh. Perfect conditions for the plugs to "look" rich. I guarantee I could go pull any plug right now, and it would be a light/golden brown. Plugs being black is bad. To much carbon. Probably from several problems we've all mentioned.
