A. Only about three minutes ago, we in the beauty department were asking ourselves the very same question—we were trying out lots of tinted moisturizers so we could recommend our favorites to you. We came up with plenty of similes, such as: A tinted moisturizer is like a fancy espadrille, and a foundation is like a patent leather pump. Meaning the former gives you just a little less polish than the latter. In fact, a tinted moisturizer, like an untinted one, delivers humectants—often along with a range of other ingredients, like antioxidants—but it also contains iron oxides and possibly titanium dioxide at about 3 percent to deposit color, says Yoram Fishman, founder of 220 Labs, which develops health and beauty products. A foundation contains iron oxides and titanium dioxide, too, but in the range of 14 to 15 percent, which delivers more color to the skin.
Bottom line: A tinted moisturizer hydrates and evens out the complexion; a foundation covers the skin with a layer of color and gives it a flawless finish.