MAC Blue Gaze Nail Lacquer ($16.00 for 0.34 fl. oz.) is described as a “dark periwinkle.” It’s a bluish purple with a cream finish. At a glance, it’s indigo, and when you look more closely, there’s a definite, strong blueness to the color. SpaRitual blue Moon is a touch purpler and has shimmer. MAC Breezy Blue is similar. Deborah Lippmann I Know What Boys Like is bluer.