Hair to Dye For

To Camouflage Roots

Get a root cover-up kit but go a shade lighter than you think you should, Petrizzi says. Always comb the color slightly beyond your roots so that there's a smooth shade transition.

Try Revlon Root Erase by ColorSilk ($4, drugstores)

Make It Last

If you've got some regrowth before you're ready for another coloring session, conceal it by zigzagging your part. Also, don't let styling products accumulate on your hair: The buildup makes roots more obvious. Once- or twice-weekly sessions with a clarifying wash made especially for color-treated hair, such as ColorProof Clear It Up Detox Shampoo ($30, colorproof.com for salons), should help.