Marias color formula is 3/4 ounces of 7n and 1/4 ounces of 7b mixed with 2 ounces of 20 volume developer. if maria gets her color done every month, how much product is her stylist going to need for Maria this year
9 ounces of 7n 3 ounces of 7b and 24 ounces of developer
