In a two stroke, oil is exhausted during the combustion process so some quantity of oil is normal. Black is a combination of carbon created during the combustion process, and on newer engines, wear particulates departing the engine. A lot or a little is a subjective call based on a users viewpoint, so making a call on the quantity without physically seeing it, and knowing how many flights it took to accumulate, is impossible.

Glow and gas exhaust will always be different in color, with gas exhaust most always being black.