Can You Mix Different Brands of Hair Colour in One Bowl?

No: keep each bowl to one brand, because Schwarzkopf, Wella, L'Oréal and Matrix each write their shades, developer and ratio for their own range only (Schwarzkopf mixes IGORA ROYAL 1:1, L'Oréal mixes Majirel 1:1.5), so a two-brand bowl is off-instruction for both tubes. Changing brands between services is a different matter: the manufacturers' conditions cover what type of colour went on before and the state of the hair, and none names a brand.

Can you mix different brands of hair colour?

No: brands write intermixing rules only for their own ranges. Schwarzkopf, Wella, L'Oréal and Matrix also pair their colour with their own developer at their own ratio, and none mentions other brands, so a two-brand bowl sits outside all of their instructions.

Schwarzkopf Professional's GB IGORA ROYAL Technical Manual calls a shade "perfectly suitable for mixing with other IGORA ROYAL shades". Matrix's US 2026 Haircolor Manual restricts some mixing between its own lines: DreamAge "is a unique low ammonia base — mixing with non-DreamAge shades is not recommended". L'Oréal Professionnel's US Majirel sheet shows Majirel-family formulas only. None says anything about another company's product, and if a maker's own lines aren't always cleared to mix, there's no basis for assuming a competitor's tube is.

The ratios and developers don't line up either. Schwarzkopf's GB manual mixes IGORA ROYAL core shades 1:1 with IGORA ROYAL Oil Developer. Wella's Koleston Perfect fact sheet gives 60 g of colour to 60 ml of Welloxon Perfect. L'Oréal's global Majirel page says 1+1.5 and "use exclusively with L'Oréal Professionnel Oxydant". No single ratio and no single developer satisfies both, so at least one tube always ends up off its specified dilution. If a formula needs a tone your line lacks, use that line's own mix tones and intermix shades (for Life Color Plus, see the correctors and toners guide).

The same logic covers toners and demi-permanents. Matrix formulated its Super Sync demi NN shades for 10 volume at 1:1, and says "Any usage that is outside of these guidelines has not been validated", so topping up one brand's gloss with another's is off-instruction for the same reason. Demi developer strength is covered in demi-permanent developer strength explained.

The law is quiet on brands but firm on ratios. UK cosmetics law (Regulation 1223/2009 as retained) puts the safety duty on each product's responsible person (the company legally answerable for that product's safety) and has no provision on combining two companies' products. It does make labels for dyes such as PPD print "The mixing ratio." That matters because limits such as PPD's 2% on the hair apply to the product after mixing, and each maker works to them at its own printed ratio; an improvised two-brand ratio sits outside that calculation. HSE's hairdressing COSHH (Control of Substances Hazardous to Health) sheet: "follow the instructions for use."

What happens if you mix two different brands of hair dye?

It's untested, and the chemistry in the bowl changes. The bowl holds a dye mix, an alkaliser balance and a dilution that neither manufacturer designed, and with neither brand's dye amounts on the label, the result can't be worked out in advance. Three things shift.

The dye ingredients. A permanent shade is built inside the hair from precursors and couplers — colourless dye halves that join into coloured molecules once peroxide and alkaline conditions start the reaction. A 2025 review in ACS Omega (de Souza et al.): "The final color shade depends on the composition, quantity, and nature of all of the products used." The same review gives precursor levels running from 0.05% in lighter shades to 1.5% in darker ones — a 30-fold spread — and no tube tells you where it sits on that range.

The alkaliser. This is the ingredient in the colour tube that swells the cuticle and drives the reaction. The industry uses ammonia, MEA (monoethanolamine) and AMP (aminomethyl propanol), the last two being the usual ammonia alternatives, and choices vary even within one brand, as Matrix's DreamAge rule shows. Procter & Gamble's US patent 8,382,854 describes its Koleston Perfect as ammonia-based. Where two tubes differ in alkaliser, the bowl holds two alkaliser systems in a proportion neither maker designed.

The background dyes. Matrix's Blended and Extra Coverage shades are pre-blended with a brown/tan background, and its manual warns that mixing its Extra Coverage with its Blended and Reflect shades "can reduce gray coverage". That is within one brand's own lines, and the balance still shifts.

Permanent plus demi in one bowl is a separate question, covered in mixing permanent and demi colour in the same bowl.

Can I dye my hair with a different brand from last time?

Yes, as far as the instructions go: the conditions manufacturers set are about what type of colour or treatment went on before and the state of the hair, and none names a brand. Consult on henna, progressive colourants (home "colour restorer" products that darken gradually with each use), relaxers, perms and bleach, check porosity, run the allergy alert test exactly as the label says, then formulate the new service in one brand.

This is a sequential service: each bowl is still one product mixed to its own instructions, just as Schwarzkopf's Dual System (IGORA ROYAL on regrowth, IGORA VIBRANCE on lengths) is two bowls of one brand. Schwarzkopf's manual asks about previous colour, perm or bleach, and warns: "If hair is porous it will absorb more colour and the result may come out darker than required." Porous hair (a raised or damaged cuticle) soaks up more product, so strand-test before committing the whole head. The same manual lists IGORA ROYAL Highlifts as "Use on previous coloured hair: No". Matrix's US manual rules its colour out over henna or a progressive colourant, and asks for at least two weeks after a relaxer, perm or straightening.

The allergy alert test is the rule that doesn't bend for history. Matrix requires it 48 hours before every application, "even if you have previously applied this product or another colorant on your client"; Wella says "before each coloration". The legally required label warning includes "Do not colour your hair if: … you have ever experienced any reaction after colouring your hair." So a client who has reacted to any colour, from any brand, is a stop, not a re-test.

Are hair colour numbers universal across brands?

No. The big lines all put depth first and tone second, but UK cosmetics law sets no rule on what the digits mean, so the same reflect digit can name a different tone: a 3 is Matt in IGORA ROYAL but Gold in Matrix, Majirel and Life Color Plus, and a 5 is Gold in IGORA ROYAL but Mahogany on the Life Color Plus chart.

Schwarzkopf's GB manual sets IGORA ROYAL out as depth, dash, tone, where -3 is Matt, -5 Gold, -7 Copper and -8 Red. Matrix uses a level plus letters (6A, 5NJ) with numeric equivalents: .3 is Gold, M is .8. L'Oréal's US Majirel sheet labels its gold family ".3/G".

FarmaVita's 2026 Life Color Plus chart lays its codes out as level, dot, reflect — 7.44, 6.66, 10.021. Red is -8 in IGORA ROYAL, while the Life Color Plus chart files its reds as .62, .66 and .666 (6.66, for instance). Read the hair's depth yourself and pick from the target brand's own chart rather than translating a code — which is why this site doesn't publish a conversion table.

Can you mix different brands of developer and colour?

Use the developer the colour's maker names. Schwarzkopf, Wella, L'Oréal and Matrix each pair their permanent colour with their own developer, and L'Oréal says Majirel is for use "exclusively" with its own Oxydant. These are instructions, not test results, but no maker offers anything else to work to.

Developer isn't just peroxide in water: a 1990 Henkel patent (US 4,927,627) describes its preferred developer as an emulsion with a thickener, optionally stabilised and buffered to pH 3–5. It isn't shown to match any developer sold today, but developer can be more than peroxide. The alkaliser, meanwhile, lives in the colour tube: P&G's patent describes the tint component carrying "an alkalizing agent, usually ammonia". Ratio changes what reaches the hair, too. The same 20 vol (6%) bottle starts the bowl at about 3% peroxide at 1:1 and about 3.6% at 1:1.5, so the wrong brand's ratio also means a peroxide strength neither maker planned. Whatever the brand, UK law caps hair-product peroxide at 12% (40 vol).

The brand-by-brand detail is in can you mix developers across brands.

Moving clients onto Life Color Plus without a two-brand bowl

Switch at the appointment, not in the bowl. FarmaVita writes its Life Color Plus directions for its own Life Professional Cream Developer. As printed on this site's listings: 50 ml Life Color Plus to 75 ml developer at 20, 30 or 40 volume (1:1.5) as standard; 1:1 at 20, 30 or 40 volume "for a more intense color result" (the grey coverage guide covers where colourists use it); and 50 ml to 100 ml of 40 volume (1:2) "in case of super-bleaching products" (see the high-lift series guide).

For a salon moving across: don't finish old tubes by topping them up with Life Color Plus in a shared bowl — use the old brand on its own, or retire it at the client's next appointment. Re-formulate from the hair and the Life Color Plus chart rather than matching old numbers. And treat the first Life Color Plus service as a new product on that client: allergy alert test (the Life Color Plus product listing says to patch test 48 hours before applying the colour), porosity check, strand test where the history is unclear. The step-by-step is in the first-time client guide, and building a formula from the natural base in formulating from the base up.

Life Professional Cream Developer comes in 10, 20, 30 and 40 volume (3, 6, 9 and 12%); the developer decision guide and the mixing-ratios guide cover strength and ratio choice. The range runs to 160 shade, corrector and toner variants, each Life Color Plus tube at £3.49.

Summary: what's actually known

Related: Can You Mix Hair Colour Developers Across Brands?, Can You Mix Permanent and Demi-Permanent Hair Colour in One Bowl? and Switching to Life Color Plus: A Conversion Guide for Koleston and Majirel Colourists.

Colour chemistry: questions colourists ask.

Sourced to the manufacturers' own documents: Schwarzkopf Professional's IGORA ROYAL Technical Manual (GB); Wella Professionals' Koleston Perfect fact sheets; L'Oréal Professionnel's Majirel "How to Use" sheet (US) and global Majirel product page; Matrix's 2026 Haircolor Manual (US); FarmaVita's Life Color Plus 2026 chart and its usage directions on the Life Color Plus and Life Professional Cream Developer listings; plus Regulation (EC) 1223/2009 and its UK-retained Annex III (legislation.gov.uk); HSE SR11 Hairdressing; de Souza et al., ACS Omega 2025; and patents US 8,382,854 (P&G) and US 4,927,627 (Henkel). Always work to the current instructions supplied with the product you are using.