People are always asking me how I get my hair Silver/Grey.
Your hair needs be a base of a pure yellow/white blonde. This requires bleaching, do not attempt to do this yourself as it requires a professional.
Once you have the white base you can then begin to tone. Choose a toner with an ashy base I.e a blue or purple. Purple shampoo works just as well if left on your hair for 5-10 mins.
For winter I usually give my hair a break from the bleach and leave my roots to grow through for a few months.
I then create a dark grey to silver ombré using Scwartzkopf Igora in the shade slate grey.
I apply to my roots first, and then go back through and blend to the mid lengths. I leave this to develop for 30 mins and then rinse.
I always follow with my Re Nu hair mask to replenish my hair.