Wash hair 24 to 48 hours before coloring. Shampooing the same day as your color service strips the natural oil that protects hair and scalp.

Deep condition hair's ends. The older a strand is, the more likely it is to have been damaged by sun, wind, or styling. These damaging elements make hair's ends more porous than the hair closer to the scalp. Porous areas suck up color, creating a result that is noticeably more intense through the ends. Deep conditioning the ends 24 to 48 hours before color is added can help temporarily close the cuticle so strands don't absorb as much color. Coarse hair generally takes more time to absorb hair color, while fine hair absorbs calor more quickly.

When searching for a home hair-color shade, don't choose a color by the model on the box.

The result you achieve from a home hair color may not be exactly what you expect. A given hair-color shade actually produces a range of end results, depending on the hair-color shade you start with. That's why the back panels of most hair-color packages show you a range of color swatches so that you can determine your end result based on your starting color.

Here are a few additional steps for the home-colorists among you:

Do an allergy test, also known as a patch test, to determine whether you have any allergies to a given hair color. At least days before you plan to color hair, mix a small amount of the color - you'll find instructions for patch-test mixing included with your box of hair color. Using a cotton swab, apply a 1/2-inch (1-cm) patch of color to the inside of your elbow. Leave the area uncovered, unwashed, and undisturbed for 48 hours. Save the remaining mixture for use in the strand test. If no redness or irritation appears after 48 hours, the product is safe to use. If you do experience a reaction, you are allergic to the product so get rid of it.

Do a strand test with the color you mixed for your patch test. A strand test shows you exactly what color a home hair-color product will create on your hair. It will also give you an idea of how long a product takes to treat your hair type. Clip a few strands of hair - you want a sample that is 1/4 inch (6 mm) in diameter and at least 1 inch (2.5 cm) long - preferably from the darkest area of your hair. Bind one end of the strands with tape to keep them together. If the instructions say to apply color to wet hair, dampen the strands. Otherwise, leave hair dry Paint the strands with some of the mixed hair-color solution, then place strands in a plastic container. After about 10 minutes, rinse and dry the strands. If the color of the strand is not as rich as you would like, reapply the color solution and check every 5 minutes, up to 20 minutes for gray patches. When the strand is the color you want, note the amount of time the color has been on the strand. This indicates the amount of time you should leave the color on during the overall application.

Gather your supplies. Find some old towels, a second-hand shirt to wear, petroleum jelly or a heavy moisturizer to put around your hairline (this keeps color from seeping onto skin), and anything else you'll need - you don't want to be wandering through your house with hair color on your head. Remember, permanent dye really is permanent.