I don't have blonde hair, but I do have some very suble light brown highlights. And this was very helpeful in toning down the brassiness. Even my dyed brown hair got a tone up after using this, got a lovlier shade of brown and not the red toned brown it usually becomes.
With purple hair care products, I escape the yellow tone of my bleached hair. Adding purple neutralizes orange and yellow tones. Conditioner paired with shampoo work well, white clean hair color is somehow preserved. Hair looks well-groomed.