Bonacure pH 4.5 Color Freeze Micellar Sulfate Free Shampoo brings hair to its optimal pH4.5 level to perfectly freeze colour pigments. Use for long lasting intense colour, ideally in post-colour services and at-home maintenance. Perfect for hair that is colour treated and for clients that want to maximise colour retention. It tightens and stabilizes the matrix thus keeping the colour pigments frozen deep inside the hair and works to neutralise chemical residues while adjusting hair structure to optimal pH 4.5.