Signal White Now toothpaste instantly whitens teeth by up to one shade* Clinically proven. Its advanced technology is based on color science: the White-Correct technology with blue-sapphire pigments works like make-up products – helping to mask yellowing and whiten teeth. It contains fluoride, which protects against tooth decay.*Immediate and optical effect. Based on a clinical study in 76 subjects. Gentle on tooth enamel and helps remove stains from teeth.