Mix 1 oz. of Satin Hair Color with 2 oz. of Satin 40 Volume Developer in a small, non-metallic bowl. Apply to darkest regions of hair first. Then, apply to rest of hair while leaving approximately 3/4 inches of the roots untouched. Leave on approximately 20 minutes depending on shade desired. Afterward, apply the mixture to roots for an additional 20-25 minutes. Rinse thoroughly with lukewarm water. Then, shampoo to remove all chemicals from the hair.