MAC Girl Trouble is a slightly warm-toned, medium lavender with a pearl finish. It is a permanent nail lacquer that retails for $12.00 and contains 0.34 oz.
MAC Girl Trouble Studio Nail Lacquer ($12.00 for 0.34 fl. oz.) is described as a "super glitter pink [with a Pearl finish]." It's a slightly muted lavender with warmer, almost golden pearl/shimmer. It had semi-opaque pigmentation after two coats, while the consistency was slightly thin, but it dried down fairly quickly and didn't streak or bubble. There were a few visible brush strokes, but most of them disappeared as it dried down. NARS Night Rider (LE, $20.00) has larger sparkle. See comparison swatches / view dupes.