According to Hair Care Manual, it is recommended to wait at least four to six weeks between hair colorings. Coloring the hair too often can cause severe damage to the hair.
Hair dye damages hair by stripping off the outer layer of the hair shaft. Applying hair dye too often can lead to broken hair strands and split ends. One way to reduce the damage caused by hair dye is to wait as long as possible between colorings. Another option is to only color new hair root growth every few weeks instead of applying all-over color. Using a deep conditioner after applying hair dye can also help reduce damage.