Just For Men Shampoo-In Color H50 in Darkest Brown is a fast and easy hair dye that targets gray hairs for a natural-looking result. The ammonia-free formula is enriched with protein, vitamin E, aloe, and chamomile to nourish your hair while coloring. This no-drip formula works in just 5 minutes and lasts up to 8 weeks until gray hairs grow back.​