Should Your Hair Be Clean or Dirty Before Colouring?

This is one of the most common questions I get asked, and it’s a topic with a lot of conflicting advice online. While the old rule used to be “dirty hair is best,” the truth is a little more nuanced, depending on the service you’re getting.

Here’s a simple guide to help you prep your hair for your next colour appointment.

For Most Colour Services

For most colours, especially the gentle, ammonia-free formulas I use, clean hair is best.

The old advice to come in with dirty hair was based on the idea that your natural oils would protect your scalp from harsh, ammonia-based dyes. However, modern colour formulations are much kinder to your scalp and are designed to work best on a clean canvas.

When your hair is free from product build-up, dry shampoo, excess oils, and grey-concealing sprays or powders, the colour can penetrate the hair more evenly and effectively. This is crucial for consistent grey coverage and achieving a beautiful, vibrant result. So, a good wash the day of or the day before your appointment is perfect.

For Bleach Services

This is the one exception to the rule! If you’re coming in for a solid bleach application, it’s best to have a little build-up.

Your natural oils provide a protective barrier on your scalp that can help prevent irritation and discomfort during the bleaching process. So, for a full-head bleach, skip the hair wash for a day or two beforehand.