Schwarzkopf BC pH 4.5 Color Freeze Silver Treatment Mask 200ml is an intensive treatment that restores and also neutralizes yellow tones on very light blonde or white hair colors. Specially developed to provide in-depth care, the composition resorts to Amino Acids to fill structural gaps from the outer layer of the hair to the cortex. At the same time, the Color Freeze Silver Treatment Mask also contains the exclusive pH 4.5 Balancer Technology. This patented innovation not only restores the hair to its optimal pH value, but actually stabilizes and strengthens the hair matrix, keeping the color pigments locked inside the hair. Lastly and as previously mentioned, the Color Freeze Silver Treatment Mask helps to neutralize unwanted warm undertones, preserving and reviving cool tones. The result? In a single step, your color is revitalized and restored to its true essence!