Bigen 37Bigen Permanent Hair Color is ideal for those looking for long lasting, excellent grey hair coverage or to enhance their natural hair color. A proven formula for over 30 years with effective results, the unique powder formula is activated by water and deposits rich, natural-looking color into even the most stubborn gray hair. With no ammonia required, this deposit-only color is the gentle choice for rich color and optimum shine regardless of your natural hair color, consistency, condition, length or style!