Wella Professional Welloxon Perfect 1.9% 6 Vol Creme Developer - 1000ml Wella's classic Welloxon Perfect developer ensures that you reach the most accurate hair colour possible when completing yourself. Available in a variety of volumes, the Welloxon range has been specifically reformulated to achieve the best results on all hair types. This 1.9% Developer will provide up to a few levels of lifting, making it ideal for any bleaching technique without sacrificing the hair's natural shine or moisture.