We love this gentle formula that not only works wonders to brighten blonde and brown ... with purple shampoo and conditioner, ...

She was especially impressed by how well this purple shampoo ... this blonde-prolonging shampoo. Why We Love It: This formula from Olaplex allows already light hair to reach peak vibrancy ...

"It also means that blonde hair absorbs light instead of reflecting it and is more prone to damage," adds Shiel. How to use purple shampoo This may seem obvious, but a violet-based shampoo is not ...

What you really need? A purple shampoo. Yep, unlike darker brown hair colours, blonde hair has an annoying tendency to fade and become brassy. Thankfully a toning purple shampoo can help prevent this.