Don't Overhue It
“Don’t go more than two shades lighter or darker than your natural hair,” says Nikki Lee, a colorist and the owner of Nine Zero One salon in Los Angeles. “Going from very dark to very light requires multiple processes, and the chances of someone having everything that they need to achieve that at home are slim to none!” Root touch-ups are easy to do at home, however. Give that base a boost with L’Oréal Paris Magic Root Cover Up Spray ($9).
Your Eyes Deserve Complements
If you have warm-toned eyes, like amber or hazel, a warm hair color will look good on you, says Lee. Conversely, blue- and gray-eyed babes should opt for a cooler shade.
If you want to try out a new shade (or eke out a little time between salon appointments), semipermanent formulas, like Clairol Natural Instincts Semi-Permanent Color ($9), are low-commitment options. They coat the hair strands on the outsides only and wash out in a few weeks.
Double Down on Long Locks
Most boxed dyes are designed for hair that’s shoulder length or shorter. If your hair is more Busy Philipps than Michelle Williams, you should grab two boxes of color at the store, says Will Francis, a colorist with NYC's Sally Hershberger/Tim Rogers salon.
When It Comes to Grays, Go All the Way
The only formulas that will work on thick, wiry gray hairs are permanent dyes, which penetrate the hair shafts and deposit color inside. (Semipermanent dye sits on the surface.) We like Garnier Nutrisse Ultra-Coverage Nourishing Color Crème ($33 for two).
Put Yourself to the Test
If you’re going to dye at home, be diligent about the health of your hair and scalp. Carry out a patch test on a small section of hair to check for any skin irritation or allergic reactions, recommends Nikki Lee.
Don't End Up With Tiger Stripes
What causes bad highlights? “When the contrast between the highlight and the base color is too far apart in shade,” says Lee. The solution? Go for a balayage home process, says Will Francis: It mimics the salon service where “highlights are hand-painted onto the hair, sans foils, for a natural-looking result.” Try Madison Reed Light Works Balayage Highlighting Kit ($45).