Just For Men Color Gel Mustache & Beard, M-55 Real Black is a brush-in gel hair color for men�s facial hair, specially formulated to eliminate gray hairs and deliver a natural-looking real black shade to beards, mustaches, and sideburns. The easy-to-use gel works quickly � typically in about 5 minutes � and lasts until the gray hairs grow back, giving a fuller, well-groomed beard appearance with minimal effort