You came home from the pool, looked in the mirror, and there it was: a faint green tinge in your blonde, or a brassy orange cast where your color used to be cool and clean. Don’t panic, and please don’t reach for the kitchen ketchup just yet. Pool-damaged hair is one of the most fixable summer beauty problems there’s, once you understand what’s actually happening at the strand level.
The short version? It’s almost never the chlorine doing the green. Here is exactly what causes it, how to strip the buildup safely, and how to keep it from happening on your next swim.
Why does pool water turn my hair green?
Your hair turns green because of copper in the water oxidizing and binding to your strands, not because of chlorine itself. Pools contain trace copper from algaecides and from corroding metal pipes and fittings. When that copper oxidizes (think of how a penny or the Statue of Liberty goes green), it deposits a greenish film onto the keratin in your hair. Chlorine plays a supporting role by speeding up that oxidation, but the pigment you’re seeing is copper. This is why light, porous, and blonde hair shows it most dramatically: there’s no competing pigment to mask the green, and porous strands grab onto minerals like a sponge.
So what makes my hair turn brassy instead?
Brassiness is a different problem: it’s the warm orange or yellow tone that shows up when the cool pigments in color-treated or lightened hair are stripped away. Sun, chlorine, and hard-water minerals oxidize and fade the toner or dye, exposing the warm underlying pigment in your hair. So green is something being added (copper), while brassy is something being removed (your cool tones). The two can absolutely happen at the same time after a summer of swimming, which is why a fix often needs two steps: remove the buildup, then re-tone.
| Green hair | Brassy hair | |
|---|---|---|
| Cause | Oxidized copper from the water binding to strands | Cool pigment fading out, exposing warm undertones |
| Looks like | Green or seaweed cast, worst on blonde and porous hair | Orange or yellow warmth, dull and flat color |
| Fix | Chelating or clarifying shampoo to lift the metal | Purple or blue toning shampoo to neutralize the warmth |
How do I remove chlorine and copper buildup?
Use a chelating (or “swimmers”) shampoo, which is specifically formulated to bind and lift metals that ordinary shampoo leaves behind. The word to look for on the label is a chelating agent such as EDTA (or tetrasodium EDTA), which grabs onto copper and other minerals and rinses them away. Regular clarifying shampoos remove oil and product buildup but aren’t always strong enough to release oxidized metal, so for green hair specifically, you want a true chelating formula. A Malibu C swimmers shampoo or a dedicated chelating shampoo with EDTA will do most of the heavy lifting. Lather, leave it on for three to five minutes, and repeat if the green persists. Follow with a deep conditioner, because chelating shampoos are intentionally stripping.
Do the DIY fixes (baking soda, ketchup, lemon) actually work?
Some help a little and some are myths, so here are the honest verdicts. Baking soda paste (mixed with a bit of clarifying shampoo into a paste, worked through and rinsed) genuinely helps because it’s mildly abrasive and alkaline, which can loosen mineral buildup. Verdict: a decent emergency fix, but harsh, so don’t make it a habit. Ketchup is the famous one, and the logic is that red neutralizes green on the color wheel. Verdict: it can mask a faint tinge temporarily, but it’s messy, smells, and doesn’t remove the copper. Lemon juice is sometimes claimed to dissolve the green. Verdict: mostly a myth; lemon is acidic and can lighten hair in the sun, but it won’t reliably chelate copper and can dry your strands out. Bottom line: a real chelating shampoo beats every kitchen remedy.
Will purple or blue shampoo fix the problem?
Toning shampoo fixes brassiness, not green, so it solves only half the puzzle. Purple shampoo neutralizes yellow tones in blonde hair, and blue shampoo neutralizes orange in darker blonde and brunette hair; both work by depositing the opposite color on the color wheel. They won’t remove copper, so if your hair is green you need to chelate first, then tone. For everyday warmth control, a quality purple shampoo used once or twice a week keeps cool blondes looking fresh between salon visits. If you want the full breakdown on getting it right, see our guide on how purple shampoo can save your hair color (or ruin it).
How do I protect my hair before I get in the pool?
The single best trick is to soak your hair with clean water before you swim, because hair already saturated with fresh water absorbs far less pool water. Dry hair is porous and thirsty; it pulls in chlorinated, copper-laden water the moment you dive in. So rinse and fully wet your hair at the shower first, then add a barrier. A leave-in conditioner or a light coat of oil coats the cuticle so the water beads off rather than soaking in. For serious swimmers, a snug silicone swim cap is the gold standard. Put together a wet-hair-plus-leave-in routine and you cut down most of the damage before it starts. We go deeper on this in our post on how to protect your hair from sun and chlorine all summer.
What aftercare does color-treated hair need?
Color-treated hair needs gentler, less frequent clarifying plus extra moisture and pigment maintenance. Chelating shampoos are effective but stripping, so on dyed or highlighted hair, limit them to roughly once a week during peak pool season and always follow with a rich mask. A swimmers shampoo and conditioner set formulated for treated hair balances buildup removal with conditioning. Between chelating washes, lean on color-safe and toning shampoos to hold your cool tones, deep-condition twice a week, and minimize heat styling so your already-stressed strands can recover.
Our Anti-Chlorine Picks
Malibu C Swimmers Shampoo
A cult favorite for lifting chlorine and copper, gentle enough for regular pool-season use.
Chelating Shampoo with EDTA
The EDTA actively binds metals, making it the most effective option for stubborn green tones.
Ion Swimmers Shampoo and Conditioner
A budget-friendly duo that removes buildup while conditioning, ideal for treated hair.
Purple Toning Shampoo
Neutralizes the brassy yellow that pool water leaves behind in blonde hair.
Leave-In Conditioner Spray
Creates a protective barrier before you swim and detangles afterward.
Silicone Swim Cap
The most reliable physical barrier; a roomy silicone style is kindest to long hair.
Prices move constantly, so we link to live listings instead of printing a number that is wrong by the time you read it. Links go to Amazon, which is where a referral gets credited.
Frequently Asked Questions
Does chlorine cause the green, or is it really copper?
It’s copper, not chlorine. The green pigment comes from copper in the water oxidizing and binding to your hair. Chlorine accelerates that oxidation, so it’s an accomplice, but the color itself is the metal. This is why a chelating shampoo that targets metals works when a plain chlorine-removing wash doesn’t.
Will purple shampoo fix green hair?
No. Purple shampoo neutralizes yellow and brassy tones, but it can’t remove copper, which is what causes green. To fix green you need a chelating shampoo to lift the metal first; you can use purple shampoo afterward if any brassiness remains.
How do I protect blonde hair at the pool?
Saturate your hair with clean water before swimming, then seal it with a leave-in conditioner or light oil so it absorbs less pool water. A swim cap adds the strongest protection. Blonde and lightened hair is the most porous, so prevention matters more for you than for anyone else.
Is a swim cap really necessary?
It isn’t strictly necessary, but it’s the most effective protection by far. If you swim often, especially as a blonde, a silicone cap dramatically cuts copper and chlorine exposure. If a cap isn’t your style, the wet-hair-plus-leave-in routine is your next best defense.
How often should I clarify my hair in summer?
For frequent swimmers, a chelating wash about once a week keeps buildup in check without over-stripping. Color-treated hair should stay on the lighter end of that and always follow with a deep conditioner. If you swim only occasionally, clarifying every couple of weeks is plenty.
The bottom line
Green hair is copper, brassy hair is faded tone, and both are completely reversible. Reach for a chelating shampoo with EDTA to clear the metal, tone with purple shampoo for any lingering warmth, and protect yourself next time by wetting your hair and adding a barrier before you dive in. Do that, and you can enjoy the whole pool season without trading away your color.
