Over toned hair refers to hair that has been colored with a toner that is too dark or too warm for the desired result. This can happen when the toner is left on for too long, or when the hair is not properly lightened before toning. Over toned hair can be difficult to correct, and it can often require multiple rounds of color correction to achieve the desired result.
There are a few things that can be done to prevent over toning. First, it is important to use a toner that is the correct color and strength for the hair. Second, the toner should be applied evenly to the hair and left on for the correct amount of time. Finally, the hair should be rinsed thoroughly after toning to remove any excess toner.