Dye-It-Yourself Hair Color

Hair color is classified as warm, cool, or neutral. “Warm colors have golden undertones and create the effect of sunlight hitting your hair,” says Christopher Cilione, a senior colorist at the Oscar Blandi Salon, in New York City. Cool shades have no golden tones at all and are best done by a professional in a salon, as they can leave you with a grayish cast. Neutral shades are a combination of both. To know which tone suits you, consider the clothing colors you look best in. If they’re warm (yellow, tomato red), go for warm shades. But if they’re cool (lavender, royal blue), choose a neutral color. Whether you go warm or neutral, the color shouldn’t stray dramatically from your natural tone. Classic rule of thumb: Stay within two shades of your own hair color, says Marie Robinson, owner of the Marie Robinson Salon, in New York City.

Step 2: Prep Properly and Thoroughly

Setting up correctly before you start coloring is crucial (for example, when jet-black dye has splattered onto the bathroom tile, well, it’s a little too late to throw down a protective drop cloth).

First, read the directions that come with the color kit. Knowing how you’ll be using the product—how long you leave it on, whether you shampoo it out or just rinse—will minimize goofs.

Second, gather everything you need, which should include an old towel to drape over your shoulders; the items in the kit, such as gloves, a brush, and a bottle applicator; a rattail comb to section hair; and clips to hold back already colored pieces.

Third, tuck your shower curtain up over the rod and place a torn-open lawn-and-leaf bag on the bathroom floor to catch drips, says Harry Josh, a colorist in Los Angeles and the international creative consultant for John Frieda. If the bag gets wet, it won’t run and stain the way newspaper would.

Finally, turn your showerhead to the gentle setting. If the flow of water is too strong, it can send dye droplets flying when you rinse, which may permanently stain tiles and grout.

For Allover Color

Middle-part dry hair with a rattail comb. Starting at the crown and working forward, squeeze the dye onto a ½-inch-wide section at the roots, then work it to the ends with your fingers. “You should feel the wetness of the formula at your scalp,” says Josh. Pile hair on top of your head while it processes for the amount of time specified on the package. Rinse.

Start with dry hair. Tautly hold a spaghetti-thin section from around your face, says Lorri Goddard-Clark, a colorist at Los Angeles’s Privé Salon. Use a color brush to swipe the highlighting solution from the roots to the ends. Release, then dab a little more onto the ends. Repeat along your part (an odd number of streaks looks more natural). Rinse according to the instructions.

If your color looks good but some natural regrowth or a few grays are starting to appear, you don’t have to dye your whole head. Either buy the same kit you originally used or get a root touch-up kit and smooth the dye down just to where your old color starts. For highlights, use a rattail comb to section off only the pieces that need color. Process according to the instructions.

Avon Advance Techniques Professional Hair Color

Often hair color intended to cover grays doesn’t—it just darkens the ends. This three-step allover-color kit results in a shiny, uniform finish. In 25 shades.

To buy: $8, avon.com.

L’Oréal Paris Healthy Look Crème Gloss Color

Want to experiment with a new look? This ammonia-free cream with built-in deep conditioners delivers in 10 minutes—and washes out in 28 shampoos. In 21 shades.

To buy: $9, walgreens.com.

Garnier Nutrisse Nourishing Color Foam

Especially good for newbies, this mousselike mixture is easy to work into hair (no danger of drips). Bonus: Testers loved the fresh herbal scent. In 18 shades.

To buy: $7, walmart.com.

Umberto Beverly Hills U Color

Long styles require more color to coat from roots to ends; this kit comes with two premixed packets of color (most have just one). In 24 shades.

To buy: $12, ulta.com.

Rita Hazan Root Concealer

Use this one-ounce aerosol to mask regrowth or grays instantly. The solution is water- and sweat-resistant and rinses clean in one shampoo. In five shades.

To buy: $25, sephora.com.