As a rule of thumb, lighter colors highlight and darker colors contour (make things look deep). Decorators and painters use this when painting. They make a room look larger by painting the focal wall dark, or the background deep.
Putting light glitter on a dark surface makes the light-colored glitters stand out against the dark surface, making them pop. So mixing very light and very dark glitter pieces together help give the nail that 3-D look. — Norma Sproles is a guest artist and educator for OPI.