Hair Colour Mixing Ratios & Development Times Compared: Igora Royal, Koleston Perfect, Majirel, INOA, Color Touch

Each maker prints its own ratio and time. Schwarzkopf gives Igora Royal 1:1 and 30-45 minutes. Wella gives Koleston Perfect 1:1 and 30-40 minutes, and Color Touch 1:2 and 20 minutes. L'Oréal gives Majirel 1:1.5 and 35 minutes, and INOA 1+1 and 35 minutes, timed from the end of application.

Those are core shades without heat. The 1:2 blonde lines are Igora Special Blonde 12- (30-45 minutes), Koleston Special Blonde (50-60 minutes) and, in L'Oréal's French and US instructions, Majirel High Lift (50 minutes on the French sheet). Pastels and toners run shorter. Below is what each maker's instructions say, and where they say nothing. Every ratio and time is the manufacturer's instruction. Amounts marked "worked out" and the in-bowl percentages are our arithmetic. Check them against the leaflet with your tubes.

Mixing ratios and development times compared

Amounts are per 60 ml tube where printed; "worked out" means we calculated it from the ratio. Ratios put colour first: 1:2 means one part colour to two parts developer. Wella labels developer in %, L'Oréal mainly in volume, and Schwarzkopf prints both; by the trade's conventional, approximate conversion, 10, 12.5, 20, 30 and 40 vol are about 3%, 3.75%, 6%, 9% and 12%.

Where this guide says a maker's documents don't say something, it means the maker documents we read for this guide.

How long do you leave Igora Royal on?

Schwarzkopf's Igora Royal technical manual gives 30-45 minutes for Naturals, Natural Extra and Fashion shades, mixed 1:1 with Igora Royal Oil Developer. The manual prints the ratio as "1:1" with no units. For a 60 ml tube of Igora Royal, equal parts works out at 60 ml + 60 ml.

On a first (virgin) application, the manual says to apply to mid-lengths and ends first and leave for 10 minutes (15 for Fashion shades), then apply to the regrowth and leave for 30-45 minutes. By our arithmetic, that gives the mid-lengths and ends at least 40-55 minutes in all (45-60 for Fashion shades), longer than the roots; that is the manual's sequence, and we found no published measurement of why the lengths go first. On a retouch, the regrowth gets 30-45 minutes, and the manual's Dual-System method on the mid-lengths and ends gets 10-20 minutes.

Other lines in the range have their own times:

• Igora Royal Absolutes: 60 ml colour + 60 ml Oil Developer, 30-45 minutes, on dry, unwashed hair. Schwarzkopf gives 9% "for white hair coverage & equalisation of up to 90% white hair", with "up to 3 levels of lift", and 6% "for pure colour deposit on more than 90% white hair". So the developer goes down, not up, once white hair passes 90%: 9% is the mix that lifts. For the lengths, Schwarzkopf's Absolutes instructions say that after 15-20 minutes (depending on the development time of the lengths product) you apply the matching Igora Vibrance shade (15-20 minutes) or Chroma ID shade (up to 10 minutes, on towel-dried hair) to the mid-lengths and ends.
• Pastels: 1:1 with 3%, 5-30 minutes. Silver Whites: 1:1 with 3%, "up to 20 minutes".
• Special Blonde 12-: "1:2 (color cream : developer)" with 9% or 12%, 30-45 minutes. Check the client's natural base first: the UK edition of the manual says the series is "To be used on bases 6 to 8", and footnotes its 4-5 levels of lift as "achievable on natural base 6 and lighter".
• Fashion Lights: 12% only, 1:1, "30-45 minutes (45 for lifting tinted bases)", and "suitable only for application off-scalp".

Choosing the developer. The UK edition of the manual sets out 3% for going darker, 100% grey, deposit and Pastels; 6% for tone-on-tone, coverage and "Lifting 1-2 levels"; 9% for "Lifting 2-3 levels"; and 12% for Fashion Lights and highlifts only. For grey, the same edition's rule is in the shade mix: Fashion shades alone up to 70% white, then 2 parts Fashion to 1 part Natural, or 1:1 for thick, colour-resistant hair. Editions differ, so check yours. More in our Schwarzkopf colour guide.

Koleston Perfect mixing ratio and development time

Wella mixes Koleston Perfect ME+ core shades (Pure Naturals, Rich Naturals, Vibrant Reds, Deep Browns) 1:1 with Welloxon Perfect. Wella's Color College fact sheet and shade-chart leaflet print "60g Koleston Perfect + 60g Welloxon Perfect", while Wella's 2020 UK fact sheet prints 60 g colour + 60 ml developer. Weigh the colour, and measure the developer the way the sheet with your tubes says. At ME+'s 2018 launch, Wella colourist Sonya Dove said the new formula "requires no habit change for colorists as it features the same mixing ratio, development time and grey coverage". Its developer guide reads:

• 12%: 3 levels of lift
• 9%: 2 levels of lift
• 6%: 1 level of lift, grey coverage, or the same depth or darker
• 4%: same depth or darker on natural hair, with no grey coverage

Wella's ladder names grey coverage only on the 6% line; it doesn't say whether 9% or 12% cover grey.

Development is 30-40 minutes without heat. With heat, Wella's own documents differ: its fact sheet says "15-20 min with heat", while its shade-chart leaflet says "15-25 min With Climazon" (Wella's heat accelerator). We have not found which is the current UK figure, so check the leaflet with your tubes.

Special Blonde is 1:2 (60 g + 120 g), with 12% for 4-5 levels of lift or 9% for 3, for 50-60 minutes (25-35 with heat). Special Mix shades are 1:1, except 0/43, which is 1:2. To refresh faded lengths, the leaflet says to apply colour to the lengths "for the last 10-15 min of the development time for the roots". See also our Wella colour guide.

Majirel: ratio and development time

L'Oréal's UK Majirel page says to mix "1 (60ml) tube to 90ml" Oxydant, a 1:1.5 ratio, and gives a "35 Minute Development time". It says 12.5 volume gives 1-1.5 levels of lift, 20 volume gives 2 levels and "is used for White hair coverage rules", and 30 volume gives 3 levels. The page's white-hair mix changes at 50% white, with a different shade mix on each side; the mixes are in our Majirel guide, linked below. The UK page gives no heat instruction; L'Oréal's French technique sheet says "Ne pas laisser pauser sous chaleur" (don't process under heat), and its US page says to "process at room temperature, without the use of heat".

Classic Majirel's maximum developer is 30 volume. 40 volume is for Majirel High Lift / Majiblond only: the French sheet uses 30 volume on natural bases 6-7 and 40 volume on bases 4-5, for up to 4.5 tones of lift. L'Oréal's French and US instructions mix High Lift 1:2, but one L'Oréal Oxydant page lists 1:1.5 for it, so check your pack. The French sheet adds that High Lift does not cover white hair (30% at most, evenly spread) and must never be mixed with classic Majirel shades. For grey coverage, see our full Majirel mixing and grey-coverage guide. Shop Majirel 60ml.

How long does INOA take to process?

L'Oréal's UK iNOA page gives a development time of 35 minutes, and is the only document we checked that states outright when the clock starts: "development time starts at the end of application". So start the timer when the last section is on; the sections you applied first will have had longer than 35 minutes; that follows from L'Oréal's wording. Its instructions for INOA 60ml:

• "mix the same amount of iNOA colour and oxydant (mix1+1)", and "Use only the indicated proportions". For a 60 ml tube, that works out at 60 ml + 60 ml.
• Use only iNOA oxydants, "10, 20 and 30 volume (9%) maximum".
• "Please do not add water".
• "Apply to root area and, if necessary, the lengths and ends." When a white-hair mixture goes on the roots, take it through with the reflect shade only.

The page gives no heat instruction, so don't add heat. L'Oréal claims "up to 100% white hair coverage", footnoted "Instrumental test, vs before colour". L'Oréal describes INOA as ammonia-free; its ingredient list includes ethanolamine (MEA), which takes ammonia's place as the alkaliser. So "ammonia-free" means a different alkaliser, not none, and manufacturers' patents give ammonia's smell as a reason to replace it.

Wella Colour Touch mixing ratio and development time

Wella spells it Color Touch. Its fact sheet gives "1 part COLOR TOUCH + 2 parts COLOR TOUCH Emulsion 1.9% / 4%", which is a 1:2 ratio (for example, 30 g colour + 60 g emulsion), with a development time of 20 minutes without heat or 15 minutes with heat. Color Touch is Wella's demi-permanent line: by our arithmetic, at 1:2 the 1.9% and 4% emulsions start at about 1.3% and 2.7% peroxide in the bowl, against about 3% for a 6% permanent mixed 1:1. The same sheet gives up to 50% grey coverage for Color Touch and up to 70% for Color Touch Plus, which is also 1:2, with Color Touch Plus Emulsion 4%. For which emulsion to choose, see Color Touch 1.9% vs 4% explained.

When does development time start?

No rule covers every brand. Here is what each maker says, and where it says nothing:

• INOA: "development time starts at the end of application".
• Igora Royal Special Blonde 12-: leave on the rest of the head "for up to 15 minutes, then continue with the application to the root area and develop for another 30 minutes".
• Majirel High Lift, first application: lengths first for 15 minutes, then roots, then 50 minutes after the roots go on (French sheet). On that sequence the lengths get about 65 minutes in all.
• Koleston Perfect, refreshing lengths: the lengths go on for the last 10-15 minutes of the roots' time, so the time is measured on the roots.
• Igora Royal, Koleston Perfect and Majirel core shades, and Color Touch: the documents don't say (for Igora, the edition we searched) whether the clock starts when you begin or finish applying.

Can you use heat?

Only where the maker gives a with-heat time. Wella does for Koleston Perfect (15-20 or 15-25 minutes, as above) and Color Touch (15 minutes). Wella's leaflet ties its Koleston with-heat time to Climazon, Wella's heat accelerator; the fact sheets just say "with heat", and none of the maker documents gives a time for a hairdryer or heat cap. L'Oréal's French and US instructions say no heat for Majirel and Majirel High Lift (its UK Majirel and iNOA pages give no heat instruction). Schwarzkopf's Igora Royal manual gives no with-heat time for core shades; its only heat line, in the lightener and highlift lifting checklist, says "Please always allow the maximum development time without using heat". That line is about lifting, not every shade, but with no heat time printed, don't add heat.

A 1961 chemistry paper says heat helps dye penetrate faster, but that on the head "one is limited to the few degrees rise above room temperature that can be tolerated on the scalp", and that a steady rise is hard to rely on, "especially in the regrowth area close to the scalp where the heat is needed most". In other words, you can't count on heat warming the head evenly, least of all at the roots. We found no published basis for the makers' with-heat times; they are instructions.

Can you leave colour on longer, or change the ratio?

Time. Each maker prints a range or a single time: Koleston Perfect 30-40 minutes, Igora Royal 30-45, Majirel 35, INOA 35, Color Touch 20. The top figure is the longest the maker instructs; none of the maker documents says what happens beyond it, so going past it is outside the instructions. We found no study, independent or industry, that measures why permanent colour is processed for about 30-45 minutes; the times are instructions, not proven optimums. We also found no L'Oréal instruction to extend Majirel or INOA time for resistant grey. Cutting the time short isn't covered either: no study we found compares rinsing early with the full time.

Ratio. The ratio isn't a strength dial. It also sets how much of the tube's alkaliser and dye goes into the mix, and EU cosmetics rules on oxidative dye substances such as toluene-2,5-diamine require "The mixing ratio" on the label and set their limits "after mixing". Each maker's own developer table changes strength by changing the developer percentage at that line's fixed ratio. So change the developer, not the ratio. We found no published measurement of what a different ratio does on the head; the reason to keep it is that the label, the legal dye limits and the maker's developer table are all written for it. By our own rough arithmetic, less developer than printed also means a more concentrated dye mix, and (assuming the colour cream holds no peroxide) 6% at 1:1 starts at about 3% in the bowl, 9% at 1:1.5 at about 5.4%, and 12% at 1:2 at about 8%. The legal ceiling for hydrogen peroxide in hair products is 12% (40 volumes), and no line here prints a stronger developer.

Developer brand. L'Oréal's "Use exclusively" wording is an instruction, not a reported failure. Developer formulas can differ in carrier, stabilisers and pH buffering (the alkaliser is in the colour tube); whether one brand's differs from another's, and what a swap does, hasn't been measured in anything we found. Shop same-brand developers.

Questions people ask

How long do you leave Igora Royal on?

Schwarzkopf's manual gives 30-45 minutes for Naturals and Fashion shades, 5-30 for Pastels and up to 20 for Silver Whites.

What is the Igora Royal mixing ratio?

1:1 with Igora Royal Oil Developer for core shades. Special Blonde 12- is 1:2.

What is the Koleston Perfect mixing ratio?

1:1 with Welloxon Perfect: 60 g + 60 g on Wella's Color College fact sheet, 60 g colour + 60 ml developer on its 2020 UK fact sheet. Special Blonde is 1:2 (60 g + 120 g).

Can I mix Majirel 1:1?

L'Oréal's UK page says one 60 ml tube to 90 ml Oxydant, which is 1:1.5. A 1:1 mix is outside its instructions. By our arithmetic, 1:1 makes colour cream half the bowl instead of 40%, a quarter more per gram, and 9% developer would start at about 4.5% instead of 5.4%.

How long does INOA take to process?

35 minutes, according to L'Oréal's UK page, starting at the end of application. Don't add water.

What is the Wella Colour Touch mixing ratio?

1:2, one part Color Touch to two parts Color Touch Emulsion 1.9% or 4% (for example 30 g + 60 g). Wella's fact sheet gives 20 minutes without heat, 15 minutes with heat.

Does the timer start when you begin or finish applying?

For INOA, L'Oréal says the end of application. For Igora Royal, Koleston Perfect and Majirel core shades, and Color Touch, the documents we read don't say (for Igora, the edition we searched).

Can I leave permanent colour on longer than the instructions say?

The top of each maker's range is the longest it instructs. None of the documents we read covers going past it, so that is outside the maker's instructions.

Do I need an allergy alert test every time?

Wella says yes for Koleston Perfect: "Always perform an allergy alert test 48h before each coloration." For other brands, follow the allergy test instruction that comes with the product; the documents we read for them not mentioning one is not a reason to skip it.