Ideal to cover gray softly thanks to its formula: Bigen contains neither AMMONIA nor HYDROGEN PEROXIDE. Its beautiful and true-to-life color lasts longer than conventional colors. Bigen gives the hair a smooth silky and shiny look. Easy to use - just mix with room temperature tap water. Bigen does not require Hydrogen Peroxide. Bigen is lightly scented - there is no heavy "masking" odor because Bigen contains NO AMMONIA.