Yes, Living Proof is suitable for colour-treated hair. Their Colour Care system is specially designed to help hair colour last longer for both blondes and brunettes. Plus, their Colour Care Shampoo and Conditioner for colour-treated hair do not contain harmful ingredients like parabens, phthalates, sulfates, and silicone, which can damage coloured hair. So, if you've coloured your hair, Living Proof can be a good choice to help maintain your hair colour.