Serenity is a pale, medium periwinkle blue with cool undertones and a cream finish. It made my lips appear almost purple as it had semi-sheer coverage yet a milky quality persisted. It didn't emphasize lip lines as much as the previous three shades, but it only lasted for an hour. MAC Norwegian Sky (P, $19.00) is darker (90% similar). MAC Borealis (LE, $20.00) is lighter, cooler (90% similar). Chanel Aphrodite (792) (P, $30.00) is less pigmented (85% similar). MAC New Galaxy (P, $19.00) is more shimmery (90% similar). See comparison swatches / view dupes side-by-side.