•Before you actually decide to re-dye your hair, look at the overall condition of the hair. If the hair appears dry and brittle with a lot of split ends, you should consider conditioning it before applying any more chemicals. More chemicals now will only worsen the damage. Soak your hair in a quality hot oil treatment or a quality conditioner before you do anything.
If your hair has been dyed by a professional salon and looks to be in good condition you can re-dye it after a couple of weeks. It would be best to return to the same salon, considering the fact that your first results were good. The quality of dyes, shampoos and conditioners used in salons are usually better than what we use at home.
•If you have dyed your hair at home with good results, be sure to use the same brand of dye that you used the first time. Always stick with something you are pleased with. Cheaper hair dyes may be harsher on your hair and will result in damage that may require a professional's help to repair.
Wait as long as possible between hair colorings. The longer you wait the less your hair and skin is exposed to harsh chemicals. You should never re-dye your hair if the first coloring resulted in burning skin or any rashes in the scalp. This could be an allergic reaction to something in the dye. Check with a professional stylist.
•If you are at all unsure about dying your hair at home, you should have it done in a salon by someone who is used to working with hair dye. Using the wrong dye, or not applying it correctly, could leave your hair looking much worse than you think it did originally.
Hair dye is a chemical, and you should always handle it safely. Avoid getting the solution in your eyes, and make sure you are in a well ventilated area when you apply it to your hair. The dye will stain clothing and anything else it spills on as easily as it dyes your hair.
Once the dye has been applied to your hair and thoroughly rinsed out, follow up by using a quality shampoo and conditioner that are made for dyed hair. This will insure that your hair remains in the best condition possible.