The colour was developed with ME technology Perfect even and modern colour results Me reduces the risk of developing a new allergy to hair colour for people who are not allergic to hair dyes Although the risk of developing new allergies is reduced there is still the risk of allergic reactions which can sometimes be severe Perform an allergy test 48 hours prior to any colouring Carefully follow the safety instructions If you have already had allergic reactions to hair dye in the past You should not dye your hair ME is contained in certain nuances of the Koleston Perfect brands Pure Naturals Rich Naturals Vibrant Reds Special Blondes and Deep Browns Less hair damage with each use compared to the previous version of Koleston Perfect Valid for Koleston Perfect with Pure Balance technology