Why Does My Hair Turn Red When I Dye It Brown?
When hair is dyed brown, it is often necessary to first lighten the original hair color. This is usually done using bleach or another type of lightener, which strips away natural pigments in the hair. When the brown dye is then applied, it can sometimes interact with these remaining pigments in unexpected ways, resulting in red tones appearing in the final color. This can be especially noticeable in individuals with naturally warm or red undertones in their hair.