Instant and long-lasting whitening - Blue Foam Optical enhancers make teeth appear whiter instantly. In color science, blue and yellow are opposite colors. This toothpaste works like the blue foam disburse around teeth when brushed to offset any yellowness from stains. The result is visibly whiter teeth instantly! The immediate effect is temporary, but over time, the Dual Whitening Action in the toothpaste will whiten teeth enamel for lasting results.