The toner really is the finishing touch when achieving the optimum blonde. Highlights, or even a scalp bleach, will only get you so far. To give your blonde that warm, caramel tone or that cool, ash feel, and everything in between, you NEED the right toner.
Whilst highlights are permanent, a toner will fade - this is why you may start to feel your colour has turned brassy or has changed in-between salon visits.
Luckily this can be easily resolved! You can simply re-apply your personalised toner, allowing you to maintain your perfect blonde for even longer.