You left the salon with cool, luminous blonde. A few weeks later it's warm, yellow, or orange — and you're wondering what went wrong. The truth is, brassiness isn't a salon mistake. It's science. Every blonde has warm pigment sitting underneath, and once anything disturbs the cuticle — sun, minerals, the wrong shampoo, or simply time — that warmth starts pushing through. In this guide, our South Melbourne colour team breaks down exactly why it happens, how to fix it in one appointment, and the five at-home habits that will keep your blonde cooler for longer.