Just as blue mascara makes the whites of your eyes look brighter, blue lip gloss can make teeth look whiter. Since it's sheer, it can be layered over any other color for a subtle effect. It will also tame down unwanted warmth from your liner or lipstick. And if you get a glittery version, it can help to make your lips look fuller. To see some of the best blue glosses, check out the widget below.