Tooth enamel is not white - it is really colorless. The color comes from the way light reflects from the surface of the tooth. Toothpaste companies (and those who make money from whitening) either don't know this or don't tell the truth. Whitening softens the tooth with acids and bleaches the live part inside. This weakens teeth, causes sensitivity, sometimes gum loss and is not the way to oral health! Be careful - don't get trapped by the hype!!!