How do I get very light non brassy blonde hair color?

I want to dye my hair very light blonde. I am blonde but its brassy and I want it to have cool tones (like white blonde but not white white). My hair dresser said to use a hair color with the word ash in it but which brand or color (one you can buy in stores). If you have hair like this could you provide a picture with what you use? I would really appreciate it!How do I get very light non brassy blonde hair color?
platnone???