Dyeing dirty blonde bleached hair to lilac?

What would happen? I'm trying to go for a pastel lilac. My hair is currently dirty blonde. Would the lilac neutrilise the hair for it to go shimmer lilac or would it would a disaster? Also should I bleach again? I've been using silver shampoo and conditioner to tone it, nothing really seems to be happening because its a dirty blonde colour. What would happen if I dyed it? What should I do? Best answer 5* Thanks!:)