How often does colour need retouching?
The figure usually quoted is a little over a centimetre a month, though not all hair grows at once, so the root starts showing between the fourth and sixth week. When you need to come back depends less on the calendar than on how far your natural colour is from the one you are wearing.
If the colour is close to your own, the root takes a while to show and you can stretch to eight weeks without anyone noticing. If you wear a blonde several shades above your base, or you cover greys, the line appears sooner and reads louder, and four or five weeks is the norm.
Greys have their own logic: it is not that they grow faster, it is that the contrast is total. A head with a lot of grey wants a fixed rhythm, and stretching it saves nothing — it only makes the retouch more obvious when it finally happens.
A retouch done properly only touches the root. Running colour through the full length every time builds up pigment, dulls the tone and dries the ends, which is where that flat look comes from on hair that was only just coloured.
Between appointments, what preserves the tone most is washing with lukewarm water and using colour-protecting products. Very hot water opens the cuticle, and that is how the pigment leaves.
Where this comes from
Also in the glossary
Want to ask about your own hair?
Every head of hair starts from a different place. The best way is to tell us and have a look.
Message on WhatsApp