Debbie, apparently toners with blue in are more dangerous for staining. Not a true blue that we can see but some gray and brown toners contain blue pigments. It also depends when the hairdresser applies it - at the basin or not. Toner is supposed to just sit on your hair but if your hair shafts are open, like they do with heat, it can permanently affect your color. You should do some googling on the subject as I came across a number of ladies who reported this. Now that my hair is bright silver I am apprehensive to put anything on it and maybe mess it up!