Dyed hair: which shampoo and which care routine really make the colour last

Hair · 8 September 2026 · by María José Esteve

Colour doesn't fade on its own: hot water carries it off, as does daily washing and a shampoo that cleans more than it needs to. What really makes a difference at home, and where it stops being about the shampoo.

Colour doesn't fade: it washes out

When we colour your hair, the pigment stays inside it, under the cuticle. As long as that cuticle is closed and smooth, the colour stays where we put it. The problem is everything that opens it up: hot water, daily washing, the heat of the straighteners, the sun and shampoos that clean too harshly.

That's why colour fades on the outside before the inside. Hardly anyone ever comes in with “worn-out” colour: they come in with porous hair, which is a different thing. Porous hair soaks up the colour on the day of the appointment and then lets it go afterwards, and no shampoo in the world works miracles there.

What a shampoo for dyed hair has to do

Less than the label promises and more important than it seems: clean without stripping. A good shampoo for dyed hair is a gentle shampoo, with an acid pH that leaves the cuticle closed, and little more. It doesn't put pigment back or “fix” the colour.

If you look at anything on the bottle, let it be the surfactants. Strong sulphates —the classic sodium lauryl sulphate— clean brilliantly and carry colour off along the way. There are gentler versions and there are sulphate-free shampoos that clean perfectly well, because your hair hasn't been down a mine either.

And there's no need to look for anything exotic. A well-chosen shampoo from the chemist's or the supermarket looks after colour better than a big-name brand that strips too much. What I do advise against are the usual two: the strong anti-dandruff shampoo and the frequent-use one, which are designed for exactly the opposite.

The at-home toning shampoo: useful, and easy to overdo

Purple shampoo neutralises yellow, and blue neutralises orange. They work, and for keeping a blonde going between visits they're a real help. That said, they're dye: they deposit pigment.

The two ways to ruin it are using it too often and leaving it on too long. Once a week, two or three minutes, and alternating with your normal shampoo. On very bleached or very porous hair the pigment takes unevenly and you get that dull grey with lilac patches that we then have to remove here. If your hair is damaged, better to use it diluted in your hand with a little gentle shampoo.

And if you're brunette with highlights or you wear a warm tone, that shampoo isn't for you: you'll dull the lovely glow it has.

What matters more than the shampoo

• How often you wash. It's the number-one factor, ahead of the brand. Going from washing daily to three times a week makes colour last longer than any bottle.
• The water temperature. Warm to wash and a final cold rinse. Hot water opens the cuticle and the pigment leaves that way.
• Dry heat. Straighteners on full and the hairdryer right against your hair really do fade colour, especially reds and coppers. Always use a heat protector, and keep the dryer on medium and a hand's width away.
• Sun, chlorine and salt. They break down the pigment and leave hair porous. In summer, wet your hair with fresh water before getting into the pool or the sea: it soaks up whatever reaches it first, so less chlorine gets in.
• Your tap water. In much of Valencia it's hard, and the limescale builds up and dulls the shine. It's not an excuse: you can see it, and you make up for it with more spaced-out washes and the odd one-off chelating treatment.

What no shampoo can fix any more

There are three signs that the shower has fallen short. The first, that the tone has shifted: the ash turning golden, the chocolate going reddish. That's a warm base coming through, and it's removed with a toner, not a bottle.

The second, that the colour goes in three or four washes however well you look after it. There the problem isn't the colour, it's the hair: it's porous and doesn't hold. What's needed before the next dye is to hydrate or rebuild, and then colour onto hair that can take it.

And the third, that the colour is uneven along the length: dark at the root, dull in the middle, lighter at the ends. That's years of dye building up, and you correct it by evening it out, not by going over the top again.

The order matters: the hair first, then the colour

A toner is thirty minutes and brings the tone back without touching the colour again: it often happens that someone books in for a full colour and leaves with a toner, because what had gone dull was the glow and not the dye.

And if the hair is porous, what's needed first is to hydrate or rebuild. Colouring over hair that doesn't hold is just repeating the same disappointment in three weeks' time.