Ultimately, the end result might involve some deep, blue-based highlights if you already have nearly black hair to begin with. Or, if you have dark brown hair, a permanent blue-black color can be ...

Imagine a rich chocolate base with a hint of deep red, giving off a deliciously warm and unique vibe. This shade is perfect for those who want a little more dimension with their dark hair.

Whether you have dark blonde or brown hair, here are our top picks for the best blue shampoos for brunettes, along with expert advice from Cotto to keep your color looking fresh from the salon.