The longevity of your hair color depends upon the type and brand of the color you applied. If you've got permanent hair color, then it will stay that way until the roots grow. With touch-ups, you should expect the color to last about 6-8 weeks. In some cases, the hair dye could last about 4 to 6 months, but this range is susceptible to change based on a number of factors, including the environment and your hair-washing habits. Your hairstylist can give you some tips on how to maintain your hair color for a long time.