Get instantly* brighter teeth with Colgate Max White Purple Serum. This whitening serum is designed to be used after brushing to enhance the whiteness of your teeth using color correction technology. Your smile will sparkle from the first use. Our clinically tested technology adjusts the color of your teeth with its deep color and optical brighteners. Together, they make your teeth appear instantly* whiter. It also removes surface stains from your teeth and helps to keep your smile whiter with continual use. The cool mint and citrus flavor also freshens your breath! Safe for enamel with daily use. *The immediate effect is temporary.