How long after coloring your hair do you have to wait to color again?

Different people will give you different answers. Some say 24 hours. Some say a week or two weeks. Others will say, "let your hair rest."

My answer is that hair isn't alive. It doesn't "get better" or heal over time. The oils from the scalp do tend to condition the hair, but you can do that with conditioners. The bottom line is that each time you color treat hair, it damages the hair's backbone slightly (or more). You can color today and your hair may feel a bit drier than if you color tomorrow, but the day after tomorrow, there will be no difference.

By the way, if you want to change the color, and especially if you want to go lighter, you need to use color remover before recoloring.

What are you trying to accomplish? If you just don't like the color, it depends on what color you put on as to if you can remove, lighten, or darken it... need more info.