Naturtint Permanent Hair Color 4M Mahogany Chestnut is one of the 4 Mahogany shades. Find the right hue for you with Naturtint color chart! Similar options include 4I Iridescent Chestnut and 5M Light Mahogany Chestnut. You can go as dark as you like in one treatment, but with Naturtint, you can only lighten by one or two shades; more than that can often create unwanted brassy tones., , With ingredients derived from plants and seed oils, Naturtint plant enriched products are carefully designed for their beneficial properties to help you achieve gorgeous hair. What's extraordinary about their products is what you won't find in Naturtint vegan-friendly formulas: Zero Ammonia, Zero Artificial Fragrance, Zero Parabens, Zero Heavy Metals and Zero Sodium Lauryl Sulfate (SLS)