FIOLE BL COLOR OX3 2000ml FIOLE BL Color Developer (No. 2) A salon-grade developer for use with FIOLE BL Color. Achieve your desired results on both gray and natural black hair. This oxidizing agent is mixed with a bleaching agent, color remover, or the firstoxidizing hair color. It neutralizes the alkalinity in the No. 1 solution and lowers the pH. How to Use Mix with the first agent before application.