Why hair turns grey
Grey hair is not a colour, it is the absence of one. The pigment cells in the follicle stop delivering, and what grows out is a hair without melanin.
Something less well known happens at the same time. Greying hair accumulates hydrogen peroxide in millimolar concentrations, while catalase, the enzyme that normally neutralises it, all but disappears.
That finding comes from work by Wood and colleagues in The FASEB Journal. The practical translation: your hair bleaches itself from the inside, on top of losing its pigment.
It explains why grey hair can turn brilliant white rather than dull grey. It is not just empty, it is lightly bleached.
On stress the evidence is now serious, though more nuanced than headlines suggest. In Nature, researchers showed that acute stress in mice depletes pigment stem cells through noradrenaline, and a small eLife study followed fourteen people whose individual hairs lost pigment and later regained it.
That does not mean greying can be reversed. Fourteen participants is an exploration, not a treatment.
When the first grey hairs appear
Later than most people fear, and much less than the familiar rule promises. The 50-50-50 rule, claiming half of people are half grey at fifty, simply is not true.
A worldwide survey in the British Journal of Dermatology brought it down to six to twenty three percent, depending on ethnicity and original hair colour. Between forty five and sixty five, seventy four percent of participants did have some grey, averaging twenty seven percent of the head.
Men grey noticeably more than women. That difference shows up in almost every measurement.
The age of onset varies by background. A review in the Journal of Clinical and Aesthetic Dermatology gives the mid thirties for people of European descent, the late thirties for Asian and the mid forties for African descent.
So if you are wondering whether you are early: probably not. First grey hairs around thirty are statistically ordinary.
Why grey hair behaves differently
Grey hair often feels coarser and springs out of the shape, and there is a real structural reason for it. Where the melanin granules used to sit, microscopic voids remain in the cortex.
Those voids make the shaft lighter, more translucent and less even in density. The hair reflects light differently and feels rougher between your fingers.
What you often read, that grey hair has a tighter cuticle blocking colour, cannot be substantiated. No solid research supports that specific claim, so let it go.
The real problem with grey coverage is simpler. A hair with no pigment of its own gives the colour nothing to build on, and that is what makes an even result difficult.
Colouring grey or letting it be
This is a maintenance question, not a matter of taste. Colouring grey means an appointment every three to six weeks for years, and that commitment weighs more than any shade.
There is no medical reason to colour and none not to. The American Academy of Dermatology is blunt about the other side: there are currently no effective medical treatments to add colour back to grey hair.
What you can weigh is the middle road. Highlights or a soft balayage let grey blend into the colour instead of hiding it, so regrowth never arrives as a sharp line.
For people just starting out, with ten or fifteen percent grey, full colour is usually overkill. A demi-permanent that quiets the first greys gives more peace than permanent colour.
Which colour actually covers grey
Only permanent colour covers grey completely. Demi-permanent blends, semi-permanent does close to nothing, and that distinction decides whether you like the result.
Permanent colour
In permanent colour an alkaline agent, usually ammonia or ethanolamine, opens the cuticle. Hydrogen peroxide then oxidises the small dye precursors into large coloured molecules that can no longer escape the cortex.
That same peroxide simultaneously bleaches the melanin present. This is why permanent colour can go both darker and lighter than your natural shade, and why it reaches up to a hundred percent grey coverage.
Demi-permanent colour
Demi-permanent works without ammonia or with a minimal amount, using a low volume developer. It blends grey to roughly seventy percent, a working rule of thumb rather than a measurement, and fades without a hard regrowth line.
Semi-permanent colour
Semi-permanent contains no developer and only coats the outside of the hair. It is not designed for grey coverage and washes out over a number of shampoos.
Which hair colour suits grey hair
Stay within two shades of your original colour and go warmer than you would think. That is the shortest route to colour that does not look coloured.
Your skin greys along with your hair. A shade that looked natural at thirty often reads as harsh at fifty, because the contrast with your skin tone has grown.
Flat black is therefore almost always a mistake. It sharpens every line around the eyes and mouth and shows regrowth within two weeks.
- Naturally dark hair: dark to light brown with a warm undertone, never blue black.
- Naturally dark blonde: dark blonde or caramel keeps the contrast with your skin small.
- Naturally light: light blonde with a few lowlights adds depth without highlighting regrowth.
- A lot of grey and little appetite for upkeep: warm blonde or beige hides grey regrowth best.
- Reds: beautiful, but they fade fastest and therefore need the most touching up.
One detail people forget: the colour shown on the box was photographed on white hair. On your mix of grey and pigmented strands it will land differently.
Highlights, lowlights and balayage on grey
If you want to spend as little time as possible on upkeep, choose highlights over full colour. Grey does not disappear, it merges into the whole.
The mechanism is simple. Next to lighter pieces a grey hair no longer reads as a flaw, because it looks like one of the lighter strands.
Lowlights do the opposite and are underrated. A few darker sections give depth back to hair that greying has flattened.
Balayage only works here while your natural base still holds enough pigment. Past fifty percent grey the technique loses the contrast it runs on, and a partial colour is the more honest advice.
Read how those techniques work in the articles on balayage and airtouch.
Grey coverage and pre-pigmenting
Above fifty percent grey, pre-pigmenting is not a luxury but the reason the result comes out even. Without it the colour takes differently on grey strands than on pigmented ones.
Pre-pigmenting first puts the missing warm undertones back into the hair. Only then does the actual colour go on, now with something to build on.
Skip that step and you see two classic problems. Grey strands stay translucent, or they grab too much and turn cooler and duller than the rest.
The second key is the mix. Good grey coverage needs a natural base in the formula rather than a pure fashion shade, and a processing time that is fully served instead of rushed.
Order matters too. Grey usually sits densest around the face and temples, so that is where a colourist starts, since those sections need the longest processing.
The patch test you must not skip
Do the patch test forty eight hours before every colour, even if you have used the same brand for twenty years. This is not a formality, it is the one step that prevents serious harm.
The substance in question is paraphenylenediamine, PPD for short. It sits in nearly every permanent colour and was named contact allergen of the year by the American Contact Dermatitis Society.
EU cosmetics regulation permits PPD up to four percent in the product as sold, which after mixing with developer works out to a maximum of two percent on your head. That permission comes with a mandatory warning that the product can cause an allergic reaction.
Sensitisation can develop after years of trouble free colouring. That is exactly why the test belongs before every use and not only the first one.
In practice: a little of the mixed product behind the ear or in the crook of the elbow, left uncovered, assessed after forty eight hours. Redness, itching or swelling means the appointment does not go ahead.
Had a black henna tattoo before? Always mention it, because those often contain high concentrations of PPD and considerably raise the risk of a severe reaction.
Touching up grey roots
With full grey coverage, count on a touch up every three to six weeks. Hair grows about a centimetre a month, and with grey against dark that first half centimetre already shows.
In practice the line appears after two to three weeks and becomes obvious after five to six. Where exactly your limit sits depends on how much grey you have and how dark the colour is.
On a touch up the colour goes on the regrowth only. Taking the lengths along again loads the hair for nothing and makes the ends progressively darker and duller.
Want to go longer between visits: add highlights or go a shade lighter. Both widen the margin before grey regrowth starts to bother you.
A stopgap between appointments is root powder or a colour spray along the parting. It fixes nothing structurally, but it comfortably bridges a week.
Care, silver shampoo and colour retention
Coloured hair fades mainly through washing, heat and sun. Washing less often does more for colour retention than any expensive product.
Wait at least forty eight hours before the first wash after colouring. The colour molecules need that time to settle inside the shaft.
After that use shampoo and conditioner for coloured hair and rinse with lukewarm rather than hot water. Heat opens the cuticle and lets pigment escape.
Silver shampoo belongs in the routine as soon as your hair is white or light. The violet pigments neutralise unwanted yellow tones, but leave it on for a couple of minutes at most and not at every wash.
Overusing silver shampoo leaves a lilac or dull cast. That is not damage to your hair, but it is exactly the colour you were not after.
Grey hair also tends to be more porous and drier, so a weekly mask is not indulgence. More on daily routines under hair care.
Going naturally grey
You can stop colouring, but the transition takes months to years and that is where most people give up. With guidance that period is a good deal easier.
The harshest route is growing it out and cutting it off. That only works if you accept losing serious length or walking around with a visible line for months.
The gentler route is highlights and lowlights moving towards your natural grey. You blur the border between coloured lengths and grey roots so no hard transition ever forms.
Stripping the coloured lengths is sometimes needed when dark colour has built up. That is a chemically heavy procedure and does not belong in a bathroom.
Natural grey then asks for its own upkeep. A good cut and silver shampoo make the difference between dull grey and clear silver.
What colouring grey hair costs
With Hanna Valiullina a root touch up starts at fifty euro and colouring the lengths at seventy euro. Highlights start at a hundred euro and a fine balayage at a hundred and thirty.
Those amounts include the home visit within the service area. The final price depends on your hair length, density and how much product is needed.
With full grey coverage, budget eight to fifteen appointments a year. Highlights roughly halve that number, which narrows the yearly difference more than the individual rates suggest.
The money you never get back is spent on colour correction. A home colour that lands too dark or patchy quickly costs several times the original appointment to repair.
Grey coverage at your home
Hanna Valiullina colours at your home in Papendrecht and the surrounding area, with professional products and tailored advice. No travelling, and you spend the processing time in your own chair.
With grey coverage that matters more than it sounds. You see the result immediately in the light you wear your hair in every day, not under salon lighting that warms everything up.
Every colour appointment starts by looking at how much grey there is, where it sits and what your hair can take. See the options under services or read the broader article on hair colouring.
For an appointment or advice on which shade suits you, get in touch.
Frequently asked questions about colouring grey hair
Can grey hair be fully covered with colour?
Yes, but only with permanent colour. Demi-permanent colour blends grey away and semi-permanent colour is not built for it, so real grey coverage needs an oxidative formula with a natural base in the mix.
What is the best hair colour for grey hair?
Stay within two shades of your original colour and choose warmer than your first instinct. Dark blonde to light brown with a warm undertone softens the face, while flat black emphasises every line.
Why does hair turn grey?
Pigment cells in the follicle stop producing melanin while hydrogen peroxide builds up inside the hair. Research in The FASEB Journal showed that catalase, the enzyme that normally breaks that peroxide down, is almost absent in greying hair, so the hair bleaches itself from within.
Is the 50-50-50 rule about grey hair true?
No. A worldwide survey in the British Journal of Dermatology found that only six to twenty three percent of people are half grey at fifty, far below the rule of thumb everyone repeats.
Does plucking a grey hair make more grow back?
No, each follicle works independently, so pulling one hair has no effect on its neighbours. Plucking is still a bad idea, because emptying the same follicle for years can damage it permanently.
How often do grey roots need touching up?
With full grey coverage usually every three to six weeks, since the regrowth line becomes visible after two to three weeks. With highlights or balayage you can stretch that to eight to twelve weeks.
Do you need a patch test before colouring grey hair?
Yes, and every single time. Manufacturers of colour containing PPD specify a sensitivity test forty eight hours before every use, in line with the mandatory EU warning on the pack, even if you have coloured for years without trouble.
Can stress cause grey hair?
Research in Nature showed that in mice acute stress depletes the pigment stem cells in the follicle through noradrenaline. A small study in eLife followed fourteen people and saw individual hairs lose pigment and later regain it as stress eased.
The essentials
Covering grey works only with permanent colour, and past half grey only with pre-pigmenting. Demi-permanent blends, semi-permanent does nothing.
Choose a shade within two of your original colour and warmer than you think. If you want less upkeep, highlights beat full coverage.
And never skip the patch test, not even after twenty years of the same brand. It is the one step in the whole process you cannot undo.