Wella Koleston permanent hair colour is the first professional hair colour brand to feature breakthrough technologies Wella boasts pure and balanced colour results with natural depths and shine. Wella's Me+ Technology reduces the risk of developing a new allergy to hair colour and Wella's Pure Balance technology reduces the formation of free radicals, achieving irresistable hair quality. Wella Koleston mixing ratio is 1:1 and 1:2 for Special Blonde, has up to 100% grey coverage and up to 5 levels of lift.