Black smoke:  when an engine smoke is black, it means there is too much fuel and less oxygen in the combustion space. Too much fuel in the combustion space also means flooding of the engine. Cars with fuel injectors don’t usually flood the engine.

White smoke: when an engine emits white smoke, it means too much air in the engine and not enough fuel in the combustion space.

Blue smoke:  when an engine emits blue smoke, its means combustion of lubrication oil in the combustion space.