Need help removing brassy tones to reveal a platinum blonde? Try purple shampoo. Don’t be scared of the purple color, your hair will not turn purple. It will help counteract those dull brassy under tones to bring out a more vibrant, clear, blonde. If you look at yourself in the mirror and wonder “Why is my hair yellow?” then you need to try this, I have a feeling you’ll love it. You can find it online or any beauty supply store in your area.