The Best Shampoo for Coloured Hair (From a Richmond Colourist)
The best shampoo for coloured hair is sulphate-free, pH-balanced and matched to your specific colour type. Blondes and highlighted hair need a purple or blue shampoo to counteract warmth. Brunettes and vivids need a colour-protective formula without harsh cleansers. There is no single product that is best for every coloured head, but there are clear things to look for and clear things to avoid. This is what I tell my clients at KOHORT in Richmond.
I am Taylah, a blonde and brunette colourist at KOHORT on Bridge Road in Richmond. The question "what shampoo should I use?" sounds simple, but it is genuinely one where the wrong answer costs people money and colour longevity. I have seen clients come back after six weeks with colour that should have lasted twelve, and almost every time, part of the answer is in what they have been washing with.
I am not going to tell you to buy a specific product today. What I am going to do is explain the categories that matter and what to look for on the label, so you can make a good decision for your specific hair. Your stylist can recommend the right product for your specific colour and condition at your next appointment.
Why does your shampoo choice matter so much for colour?
Shampoo is the most frequent chemical exposure your coloured hair gets. You see your colourist every eight to twelve weeks. You wash your hair two or three times a week. That is twenty to forty shampoo applications between appointments. If each one is stripping colour molecules, the cumulative damage is significant.
The main culprits are sulphates, particularly sodium lauryl sulphate (SLS) and sodium laureth sulphate (SLES). These are powerful surfactants that create lather and clean effectively. They are also aggressive enough to open the cuticle and pull pigment out with every wash. They are not inherently evil but they are not appropriate for colour-treated hair, particularly lightened or toned hair.
A shampoo that is genuinely colour-safe does three things: it cleanses without stripping, it keeps the cuticle more closed to retain moisture and pigment, and it does not introduce ingredients that accelerate brassiness or fade.
What to look for: the essentials
Sulphate-free formula
The most important factor. Sulphate-free shampoos use gentler surfactants (look for sodium cocoyl isethionate, cocamidopropyl betaine, sodium lauroyl methyl isethionate on the label) that clean without the aggressive stripping action. The lather is often less foamy, which some people read as "less clean." It is not. The foam has nothing to do with how well the shampoo cleans. You are just used to a certain sensory experience.
Colour-safe labelling
This is not a guarantee, but it is a useful shorthand. Products labelled colour-safe have generally been formulated to avoid the most damaging ingredients for pigment. Still check for sulphates even on colour-safe products, as the labelling is not regulated and does not mean much without the ingredient check.
pH-balancing properties
Hair and scalp sit at a naturally acidic pH of around 4.5 to 5.5. Many shampoos are slightly alkaline, which opens the cuticle and makes the hair more porous over time. A pH-balanced or acidic-leaning shampoo keeps the cuticle flatter, which means better colour retention, more shine and less frizz. Some brands state this on the label; others do not. If a shampoo consistently makes your hair feel rough or dry, pH could be a factor.
Avoid high fragrance and alcohol
High fragrance concentrations and certain drying alcohols (isopropyl alcohol, denatured alcohol) can be irritating to a sensitised scalp and drying to colour-treated hair. If you have a reactive or dry scalp, these are worth checking for.
Purple and blue shampoo for blondes and highlighted hair
If your hair has been lightened, whether that is a full blonde, balayage, highlights or a toner on natural hair, this category deserves its own section. Warmth and brassiness are the natural result of pigment molecules washing out between appointments. The yellow and orange tones that appear as colour fades are not a mistake. They are just what was always underneath the lifted shade.
Purple shampoo deposits violet pigment onto the hair shaft, which sits opposite yellow on the colour wheel and neutralises it. Blue shampoo does the same for orange tones and is more effective on hair that is a deeper blonde or bronde. Used once or twice a week instead of your regular shampoo, they top up the toner between appointments and keep colour looking cooler and more intentional for longer.
The mistake people make is using purple or blue shampoo every single wash. Leave it on for too long or use it too often and you can end up with a purple or grey cast, particularly on very light or silver hair. Start with once a week, five to ten minutes, and adjust from there based on what you see. If your blonde is staying warm even with weekly purple shampoo, a gloss or toner refresh at the salon is a more effective fix than leaving the purple shampoo on longer. Our post on why your blonde turns brassy explains the full picture.
What suits different colour types
| Colour type | What to use | What to avoid |
|---|---|---|
| Platinum blonde / full bleach | Purple shampoo 1-2x week; colour-safe formula rest of the time | Sulphates, hot water, anything that opens the cuticle |
| Balayage / highlights on light base | Purple shampoo 1x week; colour-protective sulphate-free daily | Daily purple shampoo (risks over-toning), sulphates |
| Balayage / highlights on dark base | Blue shampoo 1x week; colour-safe sulphate-free rest of the time | Heavy purple shampoo (can muddy brunette) |
| Brunette / warm brown | Colour-protective sulphate-free; Kérastase Chroma Absolu range suits colour-treated brunettes well | Purple shampoo (cools and dulls warm brunette tones) |
| Vivids and fashion colour | Colour-depositing shampoo matching the shade; sulphate-free base | Clarifying shampoos, sulphates, any heat |
| Grey blending / coverage | Colour-protective sulphate-free; occasional purple or silver shampoo to keep grey tones cool | Sulphates, which yellow grey over time |
Does an expensive shampoo make a real difference?
Honestly, sometimes. The correlation between price and ingredient quality in haircare is real but not perfect. A professional or salon-only shampoo is formulated for hair that has been chemically treated, with higher concentrations of the active ingredients that matter. A supermarket sulphate-free option may be fine for maintaining colour but may not contain the bond-protecting or cuticle-sealing ingredients that a professional formula does.
Where I see a clear difference is in longevity of gloss and toner results. Clients on a professional colour-safe shampoo consistently come back with better-looking colour than those on budget alternatives, even with similar washing frequency. That said, the gap between a mid-range professional option and a luxury one is much smaller than the gap between a sulphate-free formula and a regular supermarket shampoo. Getting sulphate-free right matters more than spending the most money.
What about conditioner and treatments?
Shampoo is the first decision. Conditioner is the second. For coloured hair, conditioner should go on mid-lengths to ends, not the scalp, and it should be left on for a genuine two to three minutes rather than a quick rinse. Bond-building treatments like Olaplex or K18 used in-salon and at home help maintain the structural integrity of hair between colour services. For more on those, see our post on K18 vs Kérastase Fusio-Dose.
Beyond that, a weekly mask targeted at colour-treated hair keeps the fibre from becoming progressively drier between appointments. Ask your stylist which one suits your specific colour and hair type, the answer changes depending on whether you have lightened hair, permanent colour or a toner on top of natural hair.
Frequently asked questions
What does sulphate-free actually mean?
It means the shampoo does not contain sodium lauryl sulphate (SLS) or sodium laureth sulphate (SLES), the most common foaming agents in standard shampoos. Sulphate-free formulas use gentler cleansing agents that wash the hair without stripping colour or natural oils as aggressively.
Is purple shampoo bad for your hair?
No, when used correctly. Purple shampoo contains violet pigment that neutralises yellow tones. The issue is overuse: leaving it on too long or using it every wash can deposit too much purple pigment, leaving hair looking ashy, grey or dull. Once or twice a week for five to ten minutes is the right approach for most blondes.
Can I use a regular shampoo on coloured hair if it's sulphate-free?
Sulphate-free is the most important criterion, so yes, a regular but sulphate-free shampoo is a reasonable starting point. If it is also pH-balanced and free from harsh alcohols and high fragrance, it will protect your colour reasonably well. A professional colour-safe formula adds more targeted benefits, but sulphate-free is the baseline.
How do I know if a shampoo is making my colour fade faster?
Track how your colour looks four weeks after your appointment. If it is already looking noticeably brassy, faded or dull, and you are only washing two to three times a week, your shampoo is likely a contributing factor. Switch to a sulphate-free formula and compare at your next appointment.
Do I need a different shampoo for my scalp and my lengths?
Not necessarily, but your scalp and your lengths have different needs. Shampoo is primarily for the scalp. If your scalp needs clarifying and your lengths need gentle care, using a clarifying shampoo occasionally at the roots while applying your colour-safe shampoo through the lengths is a reasonable approach. Ask your stylist what makes sense for your specific hair.
Should I use purple shampoo if I have dark hair with highlights?
Depends on how light your highlights are. If they are a cool, light blonde, a light use of purple shampoo once a week on those sections helps maintain tone. If your highlights are a warmer bronde shade, blue shampoo is more appropriate. If your base is dark brown, be careful with purple shampoo across your whole head as it can give a dull, ashy cast to the darker sections.
What is the difference between colour-safe and colour-protecting shampoo?
Often very little. Both terms suggest the formula avoids the most damaging ingredients for colour-treated hair. Neither term is regulated, so always check for sulphates regardless of how the product is labelled. A shampoo that says colour-safe but still contains SLS is not doing much to protect your colour.