Add Yahoo as a preferred source to see more of our stories on Google. How does purple toothpaste work? It uses color theory’s principle of complementary colors. Complementary colors are shades that ...

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The reason purple toothpaste appears to work on yellowed teeth is the same reason purple shampoo works on brassy blonde hair - complementary color theory, not chemistry. Tannins from tea and coffee ...

Add Yahoo as a preferred source to see more of our stories on Google. A close up of someone smiling. At-home teeth whitening kits or toothpastes are great for getting a whiter smile at home without ...

Purple toothpaste isn't actually whitening your teeth — it's using color theory to cancel out the yellow. Purple sits opposite yellow on the color wheel, so Hismile's "color correcting serum" is ...