What Happens If You Leave Hair Dye In Too Long? (Will It Change The Color?)

We can all get distracted when dying our hair right?

That 20 minutes box dye simply triples to an hour with a click of a finger, but what will happen if we forget about it and leave the dye in too long? Will this affect our color?

The simple answer is hair dye can change color if left on for longer than the recommended time. Furthermore, if hair dye is left on too long it can cause damage to your hair.

From blonde turning a brassy color and black fading into a brown. There are many disasters that can occur when the dye is left on too long.

Most hair dyes have an official recommended time through the instructions, however, there are certain factors that can affect this time. These include;

  • Hair thickness
  • Desired color
  • Your hairs condition

Read our guide to find out all the information on what happens if you leave hair dye in too long.

Dying Your Hair With Saftey In Mind

Hair dyes are made up of a mixture of developing and semi-permanent color. Developing color works to open the cuticle and allow the permanent pigment to penetrate the cortex, where it will deposit itself for around 6-8 weeks.

Semi-permanent dyes do not open cuticles and will only penetrate up to ¾ of the way down the cortex. So it is less likely that semi-permanent dyes will damage your hair over time.

Developing color can cause damage to your hair if left on for too long as it makes it more porous, allowing the hair to become dry, brittle and rough. The result is hair that feels like straw.

dying your hair from home yourself

Therefore your hair will become extremely damaged by the chemicals in the dye which will make it look dull, dry and matted with split ends.

It is also important to keep hair dye away from your face, as it can cause irritation and inflammation if splashed onto the eyes or mouth.

Although permanent dyes are less likely to produce harmful fumes that could irritate the eyes. Always exercise caution when dyeing your hair.

Hair dye can cause an allergic reaction if it comes into contact with the eyes, mouth or scalp, leading to a burning feeling in these areas.

The most common form of a dye allergy is when a person has a sensitive reaction to ingredients in the dye solution, such as para-phenylenediamine.

Para-phenylenediamine is found in permanent hair dyes and can produce a strong allergic reaction if left on the skin too long. The rash is often very red, swollen, itchy, blistered or crusted.

According to NCBI Para-phenylenediamine (PPD) is the commonest and most well-known component of hair dyes, PPD allergy can cause severe reactions and may result in complications. 

Will Your Hair Fall Out?

Is it really possible for hair dye to cause your hair to fall out when it has been left in too long?

NEVER SAY NEVER.

There’s no proof that this is the case, but it’s probably best to avoid allowing hair dye to be left in for longer than needed.

What Happens If You Leave Hair Dye in Too Long?

Permanent Hair Dye

There is a chance that if you leave a permanent color on for too long, it will not be as vibrant as it could have been if left on the correct time period. It might fade into a yellow color as well as cause the hair to feel brittle.

If you were to have an allergic reaction then it may start to turn a green color and it would be very noticeable and people will notice.

It would take about 4-5 days for the hair dye to change colors or even more depending on your hair type or how long you leave it in.

The longer you leave it in then the darker green it will become (Not a good look right?)

This is why it is important to leave your hair dye on for the amount of time it suggests on the intersections or else there could be a few consequences.

Looking for a hair color that not only looks great but also helps to nourish your locks? Look no further than Nutrisse Nourishing Creme.

This permanent hair color comes in 42 different shades and is formulated with color boost technology. A blend of triple fruit oils: avocado, olive, and shea. Not only will you achieve beautiful, vibrant hair color with this dye kit, but your locks will also be nourished and healthy.

Garnier Hair Color Nutrisse Nourishing Creme

Semi-permanent Hair Dye

Leaving a semi-permanent hair dye on for long would not cause the hair dye to fade.

However, it will cause your hair to have a green tint to it due to the chemical reaction taking place in your hair follicle.

If you find yourself with a green tint, when you rinse out your hair dye be sure to use cold water or else the color will fade into a more greenish-grey.

It will also make your hair feel a little brittle.

Color-Boosting Semi-Permanent Hair Dye & Deep Conditioner

Looking for an easy way to give your hair a fresh, new look? Gloss+ by Boost Your Color is the perfect solution! With 11 different colors to choose from. This semi-permanent hair dye is perfect for enhancing your natural hair color or giving you a light, warm brunette shade.

Tone down Highlights or give all over color and shine with ease – without having to mix anything! Just leave it on for minutes and see the results. Crazy healthy shine included!

Will Red Hair Dye Change Color If You Leave It In Too Long?

Will red hair dye change color if you leave it in too long you ask? well, that all depends on what color you are using because red hair dye comes in many different shades.

If you leave dark red hair dye (which is more of mahogany) in your hair for too long it might cause the red to fade out and give your hair brownish-red undertones.

But if you leave light red hair dye (like a candy apple red) in for too long it will not change color at all.

It might fade out by about 1 or 2 shades, but the actual color of the dye will remain unchanged.

Adore Semi-Permanent Haircolor is the perfect way to change up your look without making a permanent commitment. This conditioning formula will give your hair a beautiful, sensual feel while leaving it free of alcohol, peroxide, and ammonia.

Best of all, Adore fades gradually over time so you can experiment with new colors any time you like – especially RED!

Adore Semi-Permanent Haircolor

Will Black Hair Dye Change Color If You Leave It In Too Long?

Black hair dye is known to have the strongest color pigment. So if you leave this in for too long it will cause your hair to fade into a brown or greenish-yellow color and then fade out completely.

This will happen whether you use an ash-based black (which has more of a blue tone) or a violet based black (which has more of a reddish tone).

Garnier Hair Color Nutrisse Nourishing Creme

Garnier Nutrisse Nourishing Creme is the perfect hair dye for dark hair. It’s formulated with color boost technology and a blend of triple fruit oils: avocado, olive, and shea, to deliver permanent hair color that leaves your locks looking healthy and shiny.

Will Blonde Hair Dye Change Color If You Leave It In Too Long?

Will blonde hair dye really change color if you leave it in too long? Yes, it can.

If you leave blonde hair dye in your hair for too long it will begin to fade into a brassy yellow color and then completely fade out of your hair.

With blonde hair being a fairly light color it can be obvious when the shade changes color , but with darker hair colors it may be less visible.

So be sure to leave the blonde hair dye on the correct amount of time before washing it out.

Garnier Hair Color Nutrisse Nourishing Creme blonde

Garnier Hair Color Nutrisse Nourishing Creme blonde

Will Brown Hair Dye Change Color If You Leave It In Too Long?

If you were to leave brown hair dye in for too long expect it to fade into a brassy orange color. Witch is a little frustrating when you are aiming for a rich brunette color.

The reason why hair dye can sometimes go brassy is because of the chemicals in it that help to lift your natural pigments and deposit another.

So if you leave brown hair dye in too long it will begin to lift some of the dark pigments out of your hair which causes a reaction creating a more orange pigmentation for a short while.

Garnier Nutrisse Nourishing Hair Color Creme

Garnier Nutrisse Nourishing Hair Color Creme brown

Read Here: How long to leave henna in as hair dye?

Will Blue Hair Dye Change Color If You Leave It In Too Long?

Yes, if you leave blue hair dye in your hair for too long it will change color.

If you are using a dark blue (like navy) it might fade out to more of a blue-black color.

But if you are using lighter blues, like royal or electric, they will not fade at all and the actual color of the dye will remain unchanged.

ARCTIC FOX Vegan and Cruelty-Free Semi-Permanent Hair Color Dye is the perfect choice when it comes to making the bold decision to go BLUE.

ARCTIC FOX Vegan and Cruelty-Free Semi-Permanent Hair Color Dye

Why Will Hair Dye Being Left On To Long Change The Hair Color

So why does hair dye change color when it is left on your hair longer than the recommended amount?

Hair dyes change colour because they are made up of two main chemicals, paraphenylenediamine (PPD) and ammonia.

As the dye is left on the hair, these ingredients break down which causes a change to how it looks. This explains why hair dye fades over time or ends up showing a different color to which you initially chose.

How to Repair Damaged Hair after Leaving Hair Dye in Too Long

Try not to freak out, you can fix damaged hair after it’s gone dry and brittle from hair dye being left on. All you need to do is use a deep conditioning treatment.  

Apply liberal amounts straight onto your dry hair, avoiding the scalp. Leave for between 20-30 minutes and then rinse off. If you can leave it on for longer, even better.

For more serious cases of dry hair, apply some olive oil to your hair after the deep conditioning treatment. Leave this on overnight, then shampoo as normal in the morning.

Doing this once or twice a week will help to restore your hair and give it a healthier appearance!

You can make your own deep conditioning treatment by creating your own homemade treatments.

Here are some simple recipes for some treatments you can easily create with some everyday products from home;

Chocolate deep conditioning treatment:

Step 1 – Heat up 1/2 cup of milk in the microwave for 30 seconds

Step 2 – Add in 2 tablespoons of cocoa powder and stir well until blended in completely

Step 3 – Apply the mixture to your hair. Depending on how long your hair is, you’ll want to use around 2 – 4 tablespoons of the mixture (enough to coat your hair thoroughly)

Step 4 – Wrap your head with a plastic bag, and wrap a warm towel over the bag for 1 hour

Step 5 – Rinse out and shampoo as you normally would.

Banana deep conditioning treatment:

Step 1 – Mash a ripe banana in a bowl

Step 2 – Apply the mixture to the hair. Depending on the length of your hair, use about half of a banana or more

Step 3 – Leave the mixture in the hair for 30 minutes to an hour. Then rinse out and shampoo as you normally would.

Aloe Vera Hair Mask:

Step 1 – Gently wash your hair as you normally would. Be sure to pat dry so that the hair does not get tangled and break off.

Step 2 – Apply a generous amount of aloe vera gel to the hair. Depending on the length of your hair, you will need about two or three tablespoons or more

Step 3 – Wrap your head in plastic wrap, then cover with a warm towel for 30 minutes. Rinse out and shampoo as you normally would.

Yoghurt Hair Mask:

Step 1 – Gently wash your hair as you normally would. Be sure to pat dry so that the hair does not get tangled and break off.

Step 2 – Apply a generous amount of yogurt to the hair. Depending on the length of your hair, you will need about two or three tablespoons or more

Step 3 – Wrap your head in plastic wrap, then cover with a warm towel for 30 minutes. Rinse out and shampoo as you normally would.

Frequently Asked Questions

Can You Leave Hairdye On Overnight?

Leaving hair dye on overnight will not cause any damage to your hair, but it will also not achieve the color you are aiming for.

Unfortunately, this will spoil the color you are aiming to achieve. You will either end up with a different variation of the color you are trying to aim for or a faded version of it.

Can you Leave Your Hair Dye on For An Hour?

Leaving hair dye on for an hour will also not achieve the color you are aiming to achieve.

Again, you will either end up with a different variation of the color or a faded version of it. An hour is too long for a box dye and will cause damage to your hair.

Even if this damage is not visible to the eye in the end it will damage your hair follicles making it hard for your hair to grow with dry and broken hair strands.

Can You Leave Hair Dye On For 10 Minutes?

Leaving your hair dye on for 10 minutes is actually the best amount of time to achieve the color you are aiming to achieve.

10-15 minutes is usually the recommended time to leave your hair dye to achieve the best results.

What Happens If You Forget To Wash Your hair Dye Off?

If you do not wash the dye off your hair for four to five days after applying it, you may see a change in how it’s meant to look. This is because the dye begins to form clumps on your strands which make give it a dull or faded look.

You shouldn’t panic if you have forgotten to wash your hair day off. As it’s unlikely to cause any major reactions or problems, just be aware that the color is not as shiny and bright as it should be.

How Long Does Hair Dye Last?

Hair dyes can last up to eight weeks or longer. This means you have up to four months of non-fade color on your head before you will need to think about re-touching it.

That said if you don’t apply your hair dye correctly and leave it on too long in the first place when dying your hair it may not last up to 8 weeks it may only last up to 2 or 4 weeks.

If your hair dye has only lasted 2 to 4 weeks then you know you have incorrectly applied your hair dye from home as it should definitely last for up to 8 weeks.

hair dye appoinyment

Read Here: How to prepare for a hair color appointment

Conclusion

After looking through the different types of hair dyes comparing different hair colors. It is clear that you should stick to the recommended amount of time the instructions recommend.

If you don’t follow the advised time to leave your hair dye on your hair, the color will not be right and may even fade entirely.

You don’t want to cause any unnecessary damage to your hair and scalp by leaving the hair dye on for too long.

Hopefully, our guide has helped you to understand the different types of hair dyes and how important it is to follow the correct times for all different colors .

It is always best to research your chosen hair dye and find out what’s right for you.

Happy colouring!

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