What does it mean if you have black skin around white penis?

Grip?: I think i know what you mean. If you usually use a tight grip around the base and rub vigorously when you're enjoying yourself alone, you'll get a dark ring around the shaft from iron pigmentation due to the microhemorrhages. It's nothing to worry about, and a majority of teens have this. Varying your technique will make this fade and make you a more versatile lover.