Sulfate-free purple shampoo for brighter blonde| Does your blonde hair not look the same as it did right after coloring? Then you need a purple shampoo for blonde hair Pureology Strength Cure Blonde. It effectively reduces unwanted yellow tones and helps to strengthen and restore damaged hair. With this purple formula, you will not only keep your color clean, but you can also restore your hair. Bring your hair back to a perfectly brilliant blonde.