How Long to Leave Crazy Colour On (and How to Apply It)

Crazy Color (often searched as Crazy Colour) says to leave it on for around 15-30 minutes after application, then rinse, or 45-60 minutes if you want a more intense result. For pale shades such as Silver it says 30 minutes, then another 15-30 if your strand test shows the colour isn't there yet. 45-60 minutes is the longest time it gives. Our tip: start timing once every section is fully covered; the brand's times run from "after application".

Below is what Crazy Color's own directions say, with the safety steps it asks for. Where something isn't covered, we say so. The full range is in our Crazy Color collection.

Crazy Color at a glance

How long to leave Crazy Color on

Crazy Color's how-to guide puts it like this: "Relax & let your colour develop. Leave it on for around 15-30 minutes after application before rinsing off. If you are after a more intense result, we suggest leaving your colour on for 45-60 minutes." Its strand-test, FAQ and professional pages give the same timings.

For comparison, a dermatology review describes semi-permanent dyes used without developer, as a class, as "left on for 20 to 30 minutes, and then rinsed off with water". That is a typical time, not a limit. Crazy Color's standard 15-30 minutes is close to it; its 45-60 minute option for a more intense result is longer.

"Develop" here simply means the time the colour sits on your hair. Nothing is mixed in to activate it, so the "development time" is the same 15-30 or 45-60 minutes.

The brand presents the longer time as an option for a stronger result, not a fix for colour that hasn't taken. To choose between them, it points you to the strand test, which uses the same timings. In practice (our guidance, not the brand's wording): note how long you left the strand, and if you're happy with it, use that same time on the full head.

Pale shades: 30 minutes, then check your strand test

Crazy Color gives one shade-specific timing. In its FAQ answers for Silver, Marshmallow, Platinum, Lavender and Lilac it says: "We recommend you leave these paler shades on for 30 minutes", and if your strand test shows the colour isn't there yet, to "leave it for another 15-30 minutes".

For the most true-to-bottle result with these shades, the same answers recommend hair that has been "bleached beforehand to a level 10 (lightest blonde)". Levels are the scale colourists use for how light hair is: dark hair sits around levels 1-5, mid-blonde around 7, and 10 is the lightest blonde. Crazy Color also warns that "You may need a few bottles of the lighter tones, even on short hair", and that a second application may be needed. Its how-to guide adds that full coverage "is even more important when you're working with pastel shades as every strand needs to be completely covered."

Can you leave Crazy Color on longer, or overnight?

Crazy Color's longest stated time is 45-60 minutes, for a more intense result. Anything beyond that is outside the maker's directions. Neither its how-to guide nor its FAQ mentions overnight use, and it gives no guidance either way on whether longer is safe or gives more colour. We found no independent test of long leave-on times under real conditions (a paste drying on the head) either, so there is no evidence in either direction. If you want a stronger result, the routes Crazy Color does give are the 45-60 minute time and its optional heat step (see "On the day" below).

Crazy Colour instructions: step by step

This is Crazy Color's own method for its semi-permanent hair colour, taken from its own pages.

Two days before: allergy alert (patch) test

Crazy Color's step-by-step directions say to do an allergy test 48 hours beforehand, and its safety section says to do one "each time you are going to dye your hair even if you are an experienced DIY-dyer".

• Dab a little colour behind your ear or on your inner elbow and let it dry.
• Leave it for 45 minutes, then rinse.
• "If you notice any reactions during the 45 minutes or during the 48 hour window, do not use the product."
• If the irritation persists, Crazy Color says to speak to your local pharmacist or GP.

(The same page's safety section, and the FAQ, say 24 hours; we've used the 48 hours from its step-by-step directions, because that is the window its own stop rule tells you to watch.) The NHBF, the UK hair and beauty trade body, notes in guidance written for developer-mixed colour that allergies can develop "even after the same product has been used many times before with no problems", and that a negative test "does not provide a guarantee that allergic reactions will not occur in the future". The same NHBF guidance names itching, redness or swelling as signs of a reaction.

For colourists: "every time" is stricter than the NHBF's example salon record card, which asks for a test at least 48 hours before a client's first colour and every six months after. The same card says the manufacturer's instructions must be followed where they set a shorter interval, so for Crazy Color that means a test before each service.

Before the full head: strand test

1. Wash your hair first.
2. Take a section about 1cm wide from the midsection at the back of your head, "where the hair won't be missed".
3. "make sure you get your protective gloves on!"
4. Work the colour in "until you are happy the hair is fully saturated in colour".
5. Leave it on for around 15-30 minutes, or 45-60 minutes for a more intense result.
6. Rinse with cold or cool water, without shampooing.
7. "If you're happy with how your strand test turned out, it's time to start colouring!"

On the day

1. Protect yourself. Crazy Color suggests "wearing old, dark clothing to prevent staining", "using disposable gloves", and a dark towel for your hair afterwards.
2. Start with clean hair. Shampoo first, then towel-dry: the brand says it "works best on both damp or towel-dried hair, whatever you prefer."
3. Prep your colour. Crazy Color suggests a mixing bowl and brush "for the best results and easy application". There is no developer to add.
4. Section with clips. This lets you "cover each inch of your hair thoroughly with colour, from root to tip!"
5. Apply from the root, section by section. "Start at the root of your hair and work in sections, making sure every section has been completely covered in colour." The guide stresses: "Saturation is key: you must completely cover each section in plenty of Crazy Color."
6. Work it in. The guide says: "Apply plenty of colour and rub between your hands until you get a creamy, thick consistency", so the result "is even, not patchy."
7. Leave it. Around 15-30 minutes after application, or 45-60 minutes for more intensity.
8. Optional heat. Crazy Color's FAQ says that to intensify the result, you can "put a cover over your hair to prevent it from drying out and use your hair dryer to add heat." It gives no dryer setting, time or type of cover, so we don't give one either. In practice (our guidance, not the brand's): keep the dryer moving, and stop if your scalp feels hot or uncomfortable. It offers heat as a way to intensify the result "even more", on top of its normal timings; it doesn't present heat as a way to shorten them.
9. Rinse. "Always rinse with cool water – cold if you can bear it!" Use the shower at high pressure and "Rinse until the water runs clear." The strand-test page adds: rinse "without shampooing, to avoid stripping fresh colour out straight away".

Expect some colour on your skin. Crazy Color's FAQ says the colours "can leave a colour stain on your hands", and older industry literature describes basic dyes, the type in most of its shades by our check of its ingredient lists, as tending to stain the scalp ("basic" is a chemistry term here, meaning positively charged, not "simple").

Should Crazy Color go on wet or dry hair?

Crazy Color's full-head how-to guide says: "Crazy Color works best on both damp or towel-dried hair, whatever you prefer." Its strand-test page says the strand test works best on "freshly shampooed, towel-dried hair or dry hair (dry hair will result in a more intense pigment transfer)". The full-head guide doesn't repeat that dry-hair line, and we found no independent test comparing the two. None of the Crazy Color pages we checked gives a separate time for dry hair: its strand-test page, which allows damp or dry hair, uses the same 15-30 minutes, or 45-60 for a more intense result. In practice (our guidance): since the strand-test page says dry hair takes colour more intensely, do your strand test on hair in the same state, damp or dry, that you'll use for the full head, so the test shows you the result you'll actually get.

Does Crazy Color work without bleach?

Crazy Color's FAQ answers "Yes you can!" for its darker shades, which it says give "a lovely glossy tonal result". It says plainly that "the results will not be as strong on darker hair as on bleached hair", and advises: "Carry out a strand test to give you an idea of the outcome."

Crazy Color gives no different leave-on time for unbleached hair; its advice is a strand test, not a longer time.

Semi-permanent dyes "do not contain bleaching agents — therefore, they cannot lighten your pre-existing shade" (Philip Kingsley's hair guide). So a pale or pastel shade can't make dark hair lighter; on unbleached hair, the shades Crazy Color points you to are its darker ones. For the pale shades, where Crazy Color recommends hair bleached to level 10 for a true-to-bottle result, getting there is a separate bleaching process not covered here, with its own damage risk and its own testing, which is why big lifts on dark hair are a job for a colourist. You can see the shades we sell on our Crazy Color 100ml page.

How long does Crazy Color last?

Crazy Color's FAQ says: "On average our Semi Permanent colours will last 10-12 washes", and that "Semi-permanent colour fades from the first wash". It adds: "The condition of your hair, how often you wash your hair and the products you use all contribute." Because the figure is counted in washes, how long that is in weeks depends on you. As rough arithmetic on Crazy Color's average: washing two or three times a week, 10-12 washes is about three to six weeks; washing every day, it's under two weeks.

You'll see other figures online. One retailer, Blue Banana, says "Crazy Color hair dyes last for 6 - 8 washes"; it gives no source, and the same page recommends applying to bleached hair for longer-lasting colour. In one lab test of a different dye on bleached hair (not Crazy Color), most of the measurable fade came in the first five washes: the first wash alone accounted for a little over a third of the change seen after ten, and no further significant change was detected between wash five and wash ten.

For aftercare, Crazy Color suggests its Anti-Bleed Spray after rinsing. Its how-to guide says it "can extend the life of your colour for up to ten extra washes", and its professional page makes the same claim, though neither cites a supporting test. "Up to" is the best case; that would be close to doubling the brand's own 10-12 wash average. To freshen colour between washes, its FAQ says: "You can add any leftover colour from your bottle into your conditioner to create a pigmented hair mask." It gives no amount.

Removing or fading Crazy Color

To speed up fading, Crazy Color suggests "an abrasive shampoo such as an anti-dandruff shampoo". It warns that blue and green shades "are notoriously more difficult to remove than other colours", which is worth knowing before you pick one if you may want to change colour soon.

For removal, Crazy Color makes Back To Base, for dry, pre-lightened hair that has been coloured with direct or semi-permanent dye. Unlike the dye, it is mixed with developer. The retail description, ours included, says it takes hair back to its pre-lightened blonde state, so it is not a way to get back to an unbleached natural colour. The retail directions, which our Back To Base product page also gives, are: mix one sachet with 2 parts 10 vol developer into a paste in a non-metallic bowl; apply in one-inch sections; leave for up to 30 minutes, checking the hair regularly; then shampoo thoroughly. Use 10 vol developer, as the directions say. Crazy Color's professional page also says "up to 30 minutes", so treat 30 minutes as the limit. That page says to check every 5 minutes and to remove it at once if the hair shows damage; that is worth doing at home too (our guidance).

Questions people ask

How long do you leave Crazy Colour on for?

Crazy Color says around 15-30 minutes after application, or 45-60 minutes for a more intense result. For its pale shades, such as Silver, it says 30 minutes, then another 15-30 if your strand test shows the colour isn't there yet.

What is Crazy Colour's development time?

"Develop" in Crazy Color's directions means leave-on time: around 15-30 minutes, or 45-60 for more intensity.

Can I leave Crazy Colour on overnight?

The longest time Crazy Color gives is 45-60 minutes. Anything beyond that is outside its directions, and neither its how-to guide nor its FAQ mentions overnight use. If you want a stronger result, its own routes are the 45-60 minute time and optional heat under a cover.

Should I put Crazy Colour on wet or dry hair?

Crazy Color's how-to guide says clean, damp or towel-dried hair, "whatever you prefer". Its strand-test page says dry hair gives "a more intense pigment transfer" for the strand test. None of its pages we checked gives a separate time for dry hair: the strand-test page uses the same 15-30 minutes, or 45-60 for a more intense result, on damp or dry hair.

Do I need a developer with Crazy Colour?

No. Crazy Color is used on its own, with nothing mixed in to activate it, and its directions have no developer step. Don't add developer or peroxide: that is outside the maker's directions.

How many washes does Crazy Colour last?

Crazy Color says 10-12 washes on average, fading from the first wash.

Do you wash Crazy Colour out with shampoo?

Not straight after dyeing. Crazy Color says to rinse with cool water, cold if you can bear it, until the water runs clear; its strand-test page says to rinse without shampooing, "to avoid stripping fresh colour out straight away".

Can I mix Crazy Colour with conditioner?

To freshen colour between washes, Crazy Color suggests adding leftover colour to your conditioner as a pigmented hair mask. For pastels, Crazy Color makes a salon product called Neutral Mix, and says: "The more you add = the creamier the shade". No ratio is given for either.

Do I need to do a patch test?

Yes. Crazy Color's step-by-step directions say 48 hours before you dye, and its safety section says to do one each time you dye. If you react during the test or the 48 hours after, don't use the product; if the irritation persists, it says to speak to your local pharmacist or GP.