Vibrant neutral blue semi-permanent dye that leaves cool tones on hair that has not been previously bleached. For best results, it is recommended that hair be lightened to a light blonde level 9 and toned before use to help avoid unwanted undertones. A little goes a long way, so it is recommended that strong pigments such as this one be used sparingly. Vegan formula helps condition hair. Color lasts 4-6 weeks.