For a long time stylists recommended that their clients arrive for their color services with dirty hair, the reason being that the natural oils would help create a barrier to protect the scalp for irritation from the hair color.
Now that hair color has become far less toxic, especially Davines hair color which is what I use, this old advice has become problematic when covering grey hair.
I actually recommend that you wash your hair 1-2 days before coloring it.
The truth is that you shouldn't get your hair dyed at all if it is dirty. Unwashed hair will not only have an excess of oil, but will also contain dirt and sweat which can affect the outcome of your color service.
Want extra points? Wash with Solu deep cleanser the night before to really create the perfect canvas for your hair color appointment.