Butter London Blagger Nail Lacquer ($14.00 for 0.4 fl. oz.) is described as a “striking cobalt blue.” That description is dead-on — this is such a rich, decadent blue. It’s royal blue, but even richer, and not quite as dark. Butter London’s impeccable cream formula shines here; rich color in two coats (but honestly, one coat is nearly opaque), smooth, even flow of the polish as you apply. I typically get a week’s worth of wear with Butter London’s formula.