Illustration: Elvis Swift
The first step in any dye job is a strand test (using a quarter-inch-wide section of hair above your ear, underneath the top layer of hair). Note exactly how long the dye should stay on to reach your desired color. (If you're using two colors, strand-test both.) If you have coarse, resistant grays, you may need to leave the dye on longer than the box prescribes. If you have processed (in particular, bleached) hair, it will absorb color more quickly and you may need to rinse before the designated time is up.
Next: 6 essential tools for at-home hair color