Hair is made up of protein. Every touch, every treatment, every style you love—it all rewrites your hair’s protein. When protein is damaged, hair’s look and feel is compromised. That’s why Nexxus uses protein science not just to repair hair but to restore its ability to perform. It isn't about one perfect hair day. It's about a lifetime of healthy hair, built strand by strand. Hair color fading is tied to the integrity of your hair’s protein structure. Every exposure to physical, thermal, or chemical stress weakens keratin structures, making hair more vulnerable over time. Color treatments—like bleach, highlights, and dyes—with high pH can raise the cuticle and expose the inner cortex, leaving hair vulnerable to breakage and tonal irregularity. Over time, this damage compromises optical clarity and allows color molecules to diffuse when hair is exposed to water, accelerating fade. As a result, colored hair can appear dull, flat, and lifeless. Color Assure, our vibrancy and anti-fade collection, is powered by CHROMABOND SEALER technology with citric acid to lock color molecules inside the protein matrix and seal the cuticle barrier. This advanced shampoo for color treated hair and conditioner for colored hair system combines citric acid bond strengtheners with ionic sealing technology to repair color-induced damage and create a smooth, reflective surface—so your color stays vibrant, multidimensional, and radiant for up to 40 washes. Nexxus, the protein science behind powerful hair since 1979.