text: permanent vs. semi-permanent hair dye? since i have to re-dye about every four weeks because the roots show, is there any advantage to permanent color?  i don't care if it lasts 6 weeks, if i have to color every 4 weeks.  or does permanent color cover better? semi-permanant color lasts up to 6 weeks. that just means that it will fade off a little bit. you cannot control how much your hair grows.  it grows a 1/2 inch every monthy on average. therefor, you will always need to color it every 4 to 6 weeks. to keep your hair healthier, i would suggest that you see a professional because it is relaxing and easier, plus everyone can tell if you color your own hair. trust me. if you keep doing it at home, then do a retouch when needed and on the 2nd time that you would retouch the roots, pull the color to the rest of your hair the last 5 minutes to refresh it. you can use whatever you prefer too-semi or permanant.  i would use permanant to prevent fading. and don't forget a color safe shampoo! hope this helps!