How Long To Leave Hair Dye In. In the case of mid-level color you should keep the dye in for 20 minutes. Other dangers of bleaching In.
No matter how permanent or semi-permanent the dye is leaving it on overnight will not make it darker. Never leave the dye in your hair for less than thirty minutes or more than forty-five minutes. The last 15 minutes are for.
How to apply the hair dye.
The last 15 minutes are for. The maximum amount of time you should leave bleach on your hair is 30 minutes. How long you should leave it in for will vary by brand but 30 minutes to an hour is typical. The hair dye needs 30 minutes for the ammonia and peroxide to work its way into the hair cuticle to change the hairs natural pigment.