Colour-treated hair care: how to make the colour last
10 min read Hair concerns Updated 5 October 2026 By Anna Sophie Schulenburg
Colour-treated hair is dyed hair, and caring for it means letting as little colour as possible run down the drain with every wash. Wash two or three times a week in lukewarm water, massage shampoo into the scalp only and always follow with conditioner on the lengths. After a fresh colour appointment, wait 48 to 72 hours before the first wash, put heat protectant on before blow-drying and wear a hat in the midday sun. Whether that is enough shows in a daylight photo taken four weeks after the appointment, compared with one from day three.
What colour-treated hair means and what dyeing does to it
Colour-treated simply means dyed: the hair has been coloured, at the salon or at home. In everyday use the term covers permanent colour, demi-permanent colour and semi-permanent tints, and often highlights and bleach too. For your care routine, what matters is how deep the colour goes into the fibre and how much the fibre was stressed on the way.
| Type of colour | What happens in the hair | How the colour fades |
|---|---|---|
| Semi-permanent tint | The dye molecules settle on the outside and in the outermost layer of the fibre | Washes out gradually over a few weeks |
| Demi-permanent colour | A little developer lets the colour partly penetrate the fibre | Fades over several weeks, with a soft regrowth line |
| Permanent colour | Ammonia or a substitute lifts the cuticle, and hydrogen peroxide makes the colour precursors react into large molecules inside the fibre | Stays until it grows out, but loses vibrancy with every wash |
| Bleach | Your own pigment is broken down and internal bonds are weakened | Grows out, and the tone drifts towards yellow over time |
| Henna | The plant dye binds to the keratin in the outer layers of the fibre | Lasts a long time and is hard to colour over |
After permanent colour, the cuticle lies rougher than before. The hair is more porous: it soaks up more water in the shower, swells more and releases a little pigment each time. Warm water increases the swelling. Reds and coppers fade fastest, because their dye molecules are smaller and wash back out of the fibre more easily. The rough surface also scatters light, which is why coloured lengths look duller over time than freshly coloured roots.
Self-check: what your colour-treated hair needs right now
| What applies to you | What is behind it | What your care aims at |
|---|---|---|
| Same or darker shade, only the roots are recoloured, the lengths feel supple | Slightly porous, otherwise intact fibre | Holding the colour: control water, heat and light, light moisture care |
| Two weeks after the appointment the colour is visibly paler | The pigment is washing out too fast | Check water temperature and wash rhythm, rules 2 to 4 below |
| The lengths are coloured at every appointment and are darker and duller than the roots | Colour has built up in the lengths, the surface is rough | Have only the roots coloured next time, a mask once a week |
| Wet lengths stretch like rubber and snap when you comb them | The inner structure is weakened, usually after lightening | Bond care and less heat, colour comes afterwards |
| Grey roots show again after three weeks | Grey regrowth stands out, and the darker the colour, the sooner | Refresh the roots more often or plan the transition to grey |
Do two rows apply to you? The free hair analysis asks about colour type, hair thickness and care one by one.
If your hair is bleached or has been lightened several times, deal with the weakened structure first and the tone second. Different rules apply when you want to care for bleached hair. If you are letting the colour grow out and your grey come through, you need care for grey hair without a yellow tinge more than colour protection.
First wash after colouring: why 48 to 72 hours
Wait at least 48 to 72 hours before washing freshly coloured hair. That is the usual salon advice, and the reason is chemical. Permanent colour works in an alkaline environment that opens the cuticle. Once it is rinsed out, the fibre needs time to return to its slightly acidic normal state and for the cuticle to settle. During that window the fresh pigment is at its loosest, and each wash takes more of it with it than later on.
Waiting is no problem for hygiene either. At the salon the colour was rinsed out thoroughly and often finished with an acidic aftercare treatment; with a box dye, the conditioner in the pack does that job. If your roots need help before then, use a dry shampoo.
Do the first wash itself in lukewarm water with a mild shampoo, then conditioner. If the water runs slightly tinted, that is excess pigment from the surface. A clarifying shampoo has no place in your bathroom for the first two weeks.
How to make hair colour last: 10 rules for colour-treated hair
- Wait 48 to 72 hours after colouring before the first wash.
- Wash two or three times a week and bridge the days in between with dry shampoo at the roots. If your roots get greasy faster, your rhythm depends on how often you should wash your hair, and the shampoo stays on the scalp all the more.
- Set the water to lukewarm, closer to hand-warm than shower-warm, for the whole wash.
- Massage shampoo into the scalp only. The lather running down cleans the lengths.
- Use a mild shampoo and save clarifying and anti-residue shampoos for the week before your next colour appointment.
- Apply conditioner from ear level down after every wash. It smooths the cuticle, and a smooth surface holds pigment better.
- Spray on a heat protectant for your hair before the hairdryer, straighteners or curling tongs, and set straighteners to 180 °C at most.
- Protect the colour from the sun: a hat or scarf at midday, and a UV spray only if it is labelled as one.
- Wet your hair with tap water before swimming, put a leave-in on the lengths and rinse out chlorine or salt water straight afterwards. At the seaside this is part of your wider summer hair care, along with a hat and shade.
- When you recolour, have only the roots done and refresh the lengths with a tint or a gloss at most.
When the colour fades or turns brassy
The table starts with the most common triggers. You can fix the first two without buying anything new.
| What you see | Where it usually comes from | What you change |
|---|---|---|
| The colour gets paler week by week | Hot water, daily washing, shampoo down to the ends | Lukewarm, two or three times a week, shampoo on the scalp only |
| The lengths are dull, the roots shine | Rough cuticle from heat and friction | Heat protectant, hairdryer on medium at 15 cm, conditioner at every wash |
| Red turns orange, brown turns reddish | The artificial pigment washes out and the warm undertones show through | Rules 2 to 4, plus a refresh at the salon |
| Blonde turns yellow or brassy | Warm undertones after lightening, plus sun | Purple shampoo, see below, and sun protection |
| A green tinge in light lengths after the pool | Copper from the water settles in porous fibre | Wet the hair first, swimming cap, rinse straight afterwards |
| The lengths get darker with every appointment | Colour is pulled through the lengths again and again | Tell your colourist to colour the roots only |
A hair care routine for colour-treated hair in four steps
The amounts are for shoulder-length hair. For chin-length hair use about half, for chest-length hair about double.
Step 1 — Wash. Massage a walnut-sized amount of shampoo into the scalp only with lukewarm water and rinse thoroughly. For fine to medium hair the MONAT Advanced Hydration System fits, for thick, dry hair the Renew™ System. If your lengths feel rubbery when wet, the Bond IQ™ line is the better base.
Step 2 — Condition. Spread conditioner through the lengths and ends from ear level down, leave it on for two to three minutes and detangle with your fingers in the meantime. Once a week a mask replaces the conditioner, for example the Super Moisture Mask for dry lengths and the Replenish™ Mask for often-coloured lengths, for five minutes. If the lengths hang limp rather than soft after the mask, it was too much, so use half next time.
Step 3 — Protect. Squeeze the hair out with a towel and work a pea-sized amount of leave-in, meaning care that stays in the hair, through from ear level down, for example the Restore™ Leave-In Conditioner. Before blow-drying, add the Studio One™ Thermal Protect Shield, sprayed evenly over the lengths and combed through briefly.
Step 4 — Finish. Warm one or two drops of REJUVENIQE® Oil between your palms and press it into the ends only. If the ends look stringy afterwards, one drop is enough. The oil does not replace heat protection, so it goes in after blow-drying, or into towel-dried hair before air-drying.
Purple shampoo, vinegar and camomile: what works?
- Purple shampoo helps with blonde, light highlights, grey and white. Its violet pigment sits opposite yellow on the colour wheel and tones down the yellow cast. For red, copper, gold and other deliberately warm shades it is the wrong choice because it makes them dull, and on dark brown or black you will see nothing from it. Brown with an orange cast needs a shampoo with blue pigment. Use it once a week in place of your usual shampoo and stick to the time on the pack, because very light, porous hair can otherwise keep a lilac sheen.
- A cold rinse at the end does no harm. The idea that it seals the cuticle is closer to folklore; for the colour, what counts is that the water stays lukewarm through the whole wash.
- A vinegar rinse of one tablespoon of apple cider vinegar in half a litre of water is mildly acidic, and some lengths feel smoother afterwards. It does not replace conditioner and does not refresh the colour. Skip it if your scalp is irritated.
- Lemon juice in the sun lightens and dries out. On coloured hair it shifts the tone unpredictably, so leave it.
- Camomile rinses give light hair a golden-yellow sheen. For cool blonde or grey, that is exactly the tone you want to get rid of.
- A shampoo labelled “colour” or “sulphate-free” helps if it genuinely cleanses mildly, because strong surfactants release more pigment. Even so, water temperature and wash rhythm decide more about how long colour lasts than the label does.
What you see after one wash, four weeks and three months
After the first wash, check two things. If the comb glides through the lengths after conditioning without tugging, the amount is right; if it still catches, use a little more conditioner or leave it on a minute longer. The rinse water may run slightly tinted for the first two or three washes, and longer with tints and strong reds. If it is still strongly coloured from the fourth wash after permanent colour, check your water temperature and shampoo.
After four weeks, compare photos. Photograph your hair by the window in daylight on day three after colouring, and again four weeks later in the same spot. By then the roots have grown about one centimetre. If the lengths look clearly lighter or warmer in the second photo, one of the triggers in the table above is still at work.
After three months, compare lengths and roots. If the lengths are darker and duller than the fresh roots, colour has built up, and next time only the roots get coloured. If they feel rubbery when wet, your hair needs bond care before its next lightening.
When a dermatologist should take a look
If your scalp itches, burns or swells in the hours or days after colouring, or the skin on your forehead, ears, neck or eyelids turns red, see a dermatologist. A contact allergy to dyes such as p-phenylenediamine (PPD) can be behind it, and that kind of reaction can get stronger with every further colouring. With a patch test, the dermatologist finds out which substance it is. That is why box dyes ask for a skin test 48 hours before every use, even if you have used the same colour many times. If your face or eyes swell badly or you struggle to breathe, call your local emergency number straight away.
What care can do
Support cleansing, conditioning, manageability, shine, frizz control, protection from avoidable breakage and a fuller-looking appearance, depending on the product and its substantiated claims.
What it cannot do
Diagnose disease, correct hormonal causes, create new follicles or permanently fuse fully split hair ends.
Coloured but healthy
Core routine
- ADVANCED HYDRATING SYSTEM
Optional
- SUPER MOISTURE MASQUE
Sulfate-free, gentle cleansing keeps colour longer. Avoid washing too hot.
Bleached or fragile
Core routine
- Monat Bond IQ Fortifying Shampoo
- MONAT BOND IQ™ Fortifying Conditioner
Optional
- RESTORE LEAVE-IN CONDITIONER
For repeated lightening, bond care plus moisture; reduce heat.
Right away
Right after washing, colour-treated hair often looks smoother, shinier and easier to comb.
With continued use
With gentle, regular care, colour and shine can look fresh longer over a few weeks and the lengths stay suppler.
What it can't do
It doesn't refresh or change the hair colour itself, and it doesn't reverse existing structural damage.
Quick questions
Can I put permanent colour over henna?
Only after talking to your colourist. Some henna blends contain metallic salts that react with the hydrogen peroxide in permanent colour and discolour the hair or roughen it badly. So always tell the salon if there is henna in your hair, even if it was months ago.
How often can I recolour my roots?
Every four to eight weeks is usual, depending on how much the roots and lengths differ. The lengths need colour less often and get a tint or a gloss at most.
When can I go swimming after colouring?
After the first wash at the earliest, so after two to three days. Before that the pigment is at its loosest, and chlorine takes a lot of it with it.
Is dry shampoo bad for colour-treated hair?
No. At the roots it stretches the time between washes and so spares the colour. On very dark hair it can leave a white cast, so brush it out well or choose a tinted version.
Whether your coloured lengths need moisture or bond care is something the free hair analysis asks about, together with colour type and hair thickness.