Glow Zero is the permanent colour free from ammonia, p-Phenylenediamine and gluten, ideal for customers with ammonia intolerance and sensitive skin who still want extra-professional colour results. It is dermatologically tested and specific tests guarantee low quantities of heavy metals (Nickel, Cobalt and Chromium Tested). Glow Zero has a refined formula that perfectly balances precious natural active ingredients and quality pigments with a high degree of purity, guaranteeing an extraordinary cosmetic effect. There are 65 shades that can be mixed together and also used in combination with other Cotril colours. Dilution 1:1 and 1:2 for Superblondes.