MAC Romantic Overture Cremesheen Glass ($22.50 for 0.09 oz.) is described as a "clear base with sparkles." It's not quite clear--it's more like a peach-tinted base with a smattering of champagne sparkle. It definitely adds warmth to the lips, but it doesn't add much color. It lasts an hour and a half on me, unfortunately, though it is comfortable to wear. There's not much to it, so there are several similar shades that tend to look the same applied: See comparison swatches / view dupes.
A lip finish that fuses the creamy, sheen-filled nature of Cremesheen lipstick with the shine of M·A·C Lipglass. Soft, comfortable, non-sticky. Use as a top layer over its namesake lipstick or on its own.