Why you need it: Glitter polish isn't for everyone, but metallic shades are festive and fun without appearing over-the-top. Precious metals like silver, yellow gold, rose gold and bronze are classic nail colors; shades like black rhodium and green gold are beautifully unexpected.

When to wear it: Metallics feel right for parties, holidays and fancy dinners -- any celebratory occasion -- but a pretty metallic is just as versatile as any neutral.

Try...

Christian Louboutin Beauty, Miss Mars, $50. This gunmetal gray is so rock 'n' roll, and the gorgeous bottle is the ideal vanity décor.

Milk Spray Nail, Burner, $12. Milk is known for easy-to-apply beauty products, and this burnished bronze spray polish is no exception.

Ciaté London Paint Pots, Deco Delight, $15. This soft rose gold is the ideal metallic right now -- blush pink meets champagne.