Semi permanent hair dyes have become really popular with the rise of the unicorn hair trend. This sort of dye often has bright, unnatural colors or metallic and pastel finishes. Often you will get the most true results if your hair is bleached to a very light yellow color (level 10), particularly with cool shades such as blue, silver or violet. This is because this sort of hair dye (not to be confused with demi-permanent hair dyes) are color depositing only. Unlike permanent hair dyes, which use a developer and ammonia to open up the hair cuticle and can lighten hair, semi and demi-permanent dyes can exclusively darken hair. They fade over time without changing the original color of your hair too much. However, demi-permanent dye has peroxide as a developer and will slightly lighten hair a bit.

What is a Semi Permanent Hair Dye?

Unlike permanent hair dyes, semi permanent hair dyes (also called hair glosses) are deposit-only colors. This means they don’t open the hair cuticle and lighten hair, only darkening it or adding a tint or gloss. However, unlike permanent hair color, semi-permanent dyes last only for a few washes and don’t 100% cover gray hair.

Glosses are available in clear if you only want to add shine, or colors that can be used to create rainbow hair looks. You won’t need an activator to use them, and they are often vegan friendly and conditioning. You can just use it straight on your hair. Depending on your hair porosity the results will be more or less intense and long-lasting.

Best Rated Semi Permanent Hair Dyes Brands

What About Demi Permanent Hair Dye?

Demi-permanent color is a longer lasting, no-ammonia version of a permanent dye. It doesn’t lighten the hair and only deposits color, but it’s mixed with a low volume developer which will damage the hair a bit. However, it also has increased grey coverage and can be used to tone highlights, enhance your natural color or to color correct a bleach job gone wrong.

If you have grey hair that is very fine and porous you can use demi-permanent dyes to cover it. However, often the result is blended hair that looks like natural highlights instead of grey hair.

How Often Can You Dye Your Hair?

If you are using a semi-permanent hair color you can dye your hair as often as you want, because it doesn’t have anything that could damage your hair. Many people who sport unicorn hair mix a bit of their hair dye into their conditioner, to top up the color and reduce fading.

If you are wondering how often can you dye your hair with a demi-permanent dye (mixed with peroxide or other developers) then the answer is different. Semi-permanent dyes fade slowly over a period of a few weeks, but if you keep reapplying them too often they have a tendency to deposit too much color, and the peroxide will hurt your hair.

Pastel Semi Permanent Hair Dyes

If you are using demi-permanent dyes, you probably should wait around a month in between dye jobs, but it depends on your natural haircolor, your dye and the general health of your hair. If you are trying to fix a hair dye disaster (for example, removing orange from hair) you can do it more often but be fanatic about deep conditioning and protein treatments to make sure your hair doesn’t become straw like.

How Long Does Semi Permanent Hair Color Last

How long does semi permanent hair dye last depends on the brand you used, the health and porosity of your hair and whichcolor you are using. It also depends on how often you wash your hair, and how you do it. Expect to have some fading from the first wash, but I have personally managed to keep red tones from Manic Panic on my dark hair for several months.

Generally speaking Demi-permanent color stays in the hair for 12 to 24 washings, while semi-permanent only lasts for six to 12 washings. But this is a very rough average of a process that is incredibly unreliable in terms of results. As you are only depositing color, and not opening the hair cuticle fully like with permanent hair color, the end result and durability will depend a lot of the past history of the hair being dyed.

You can apply semi-permanent dye to virgin hair, and it will last much longer than if you apply it to bleached hair. This is because bleached hair (a prerequisite for anybody not naturally blonde to have unicorn or pastel hair) is much more porous and the color escapes the hair quicker when washing.

The Most Long Lasting Semi-Permanent Hair Dyes

Darker semi-permanent dyes usually last longer than pastel colors or lighter tones, but they fade to a pastel color with washes. Also, if you use heat styling that will burn out color from your hair quicker.

The brand of semi-permanent dye you use can also make a huge difference: how long does manic panic last is nowhere near as long as salon only brands such as Pravana Vivids for example. But this also means that removing Pravana Vivids is almost impossible without bleaching the hair, whereas Manic Panic can be removed with hot oil treatments and vitamin C for far less damage. It’s all about striking a balance between how often you want to re-color and how much damage your hair can take.

How long does semi permanent hair color last also depends a LOT on the aftercare. Dry shampoo will become your best friend, and cold water rinses something you deal with. Hot water, anti-dandruff or other harsh shampoos and frequent washing will fade semi-permanent hair color much quicker. If you live in a sunny climate, SPF for your hair and avoiding heat styling will also keep your bright hair rainbow-like for longer.

How To Remove Semi Permanent Hair Dye

How to remove semi permanent hair color is a frequently asked question. People often want to change the color of their hair, or decide that maybe that bright blue they got for summer is not the best color to go to work with. There are many ways to remove semi permanent hair color, and it’s a good idea to try the less damaging ones first and bring in the bigger guns (bleaching or bleach baths) if all else fails.

Timing matters. If you are wondering how to remove blue hair dye right after applying it, you are lucky because it’s much easier than after several weeks have passed and you are left with stubborn greenish-turquoise tones in your hair that refuse to go away. Generally speaking, fading semi permanent dyes until they become a pastel color is easy, the problem is getting rid of that last shades of very light pink or blue.

Start with washing your hair several times with shampoo (anti-dandruff shampoo works great) and hot water. You should see a lot of color going down the drain only by doing this.

Hot oil treatments are also great to remove semi-permanent hair dye and condition your hair at the same time. You can buy hot oil treatment kits or just applying WARM (not hot, warm, it should be pleasant and not burn your skin) olive or coconut oil, and leaving it on your hair for about 15 minutes. After this, wash your hair again with shampoo and hot water, and most of the dye should be gone.

If you want to help your rainbow hair dye fade faster you can just use hot water and clarifying shampoos regularly. If you are blonde (or have bleached your hair to get unicorn colors) you can also squeeze the juice of a lemon and covering your hair with it for about 10 or 20 minutes. Bonus points if you sit in the sun during this period.

For more stubborn semi-permanent dyes, or colors that need to be gone quickly, you can try a Vitamin C treatment. You can mix crushed vitamin C tablets with dish washing liquid and use that to wash your hair. If you have a sensitive scalp, anti-dandruff shampoo will do the trick as well but it may be slower. This works great for removing semi-permanent dyes that are vegetable based, like Manic Panic and Directions.

Hair Dye Removers And Bleaches

Many manufacturers of vivid semi-permanent hair colors have released products designed to extract them from hair. Those extractors are not the same ones used for permanent and semi-permanent dyes. They are specific for fashion colors, rainbow colors and other color depositing glosses. Performance may vary, but they can be a good thing to try if your hair is damaged by the bleaching and you can’t get rid of the remnants of a unicorn hair shade.

Bleach can be used to finish removing semi-permanent hair dyes if you want to dye your hair another light color. Otherwise you can use a darker dye on top of the faded dye to achieve a natural brunette or dark blonde (but be careful with the undertones, as you can end up with muddy green hair).

We hope to have answered all your questions about semi-permanent dye, from how often can you dye your hair to how to get hair dye out of hair or how long does semi permanent hair color last, Feel free to ask anything we missed in the comments!