Schwarzkopf BC pH 4.5 colour freeze vibrant red Micellar Shampoo for those with red hair, The caring formula will help to strengthen the structure of every strand while balancing the pH of the hair so that you're closer than ever to zero colour fade. With pH 4.5 balancer technology not only seals the surface of coloured hair as conventional colour care does but most importantly, it freezes the colour pigments deep inside the hair matrix for optimal colour.