Is it better to use a semi permanent color and just keep dying all your hair over and over or to use a permanent color and just touch up the roots? With the semi how long do they normally last? If you go with the permanent, do the ammonia free dyes really work as well as the one containing it? I dyed my hair like crazy when I was younger but stopped because it got very unhealthy. Now I have long healthy hair but I hate my natural color (ash brown ewwww) I want to keep my hair healthy. Any help would be greatly appreciated.