While toner can't directly darken the hair color, it can make it appear darker by neutralizing or reducing the appearance of brassy tones. This is because toner deposits color pigments onto the hair shaft, which can shift the overall color tone and make it appear less bright or vibrant. For instance, if your hair has unwanted brassy tones, a toner with cool, ashy pigments can help cancel those out, making the hair appear more muted and darker.
However, toner won't completely change the base color of your hair. If you want a significant color change, like going from blonde to brown, you will need to use permanent hair dye.
In summary, toner can make hair appear darker by neutralizing brassy tones, but it cannot actually change the base color.
