Permanent color is just that -- permanent. It can't be washed out if you don't like the results, so think carefully before you take this step. Plus, your roots will grow in and the ends of your hair will fade, so you're committing yourself to touch-ups -- sometimes a tricky thing to do on your own -- every four to six weeks. That said, if you want to make a major change or completely cover a lot of gray (about 50 percent or more), this is the process for you. Just keep in mind this rule of thumb: The farther from your natural color, the higher the maintenance. (If you're interested in wild colors like purple or orange or in lightening more than two shades, see the Double-Process section.)
There are plenty of permanent colors available for home use, and they're pretty easy to use. However, it's a good idea to have a colorist take on the job, especially for first-timers. These professionals have experience with a wide range of products and can custom-mix colors to give you just the results you want.
Two simple chemicals make all permanent colors work: hydrogen peroxide (sometimes called a developer or an activator) and ammonia (or something similar). These swell the cuticle, remove at least a little natural pigment and deposit the dye. Unfortunately, this process causes damage to the cuticle, and some of the protein in your hair is destroyed, too. To minimize the negative effects of permanent color, make sure you or your colorist uses one that has the least possible peroxide and ammonia. The good news is that most products on the market today are less harsh than they were in the past.