The Ultimate Guide to Semi-Permanent Hair Dye

15th Jan 2024

What is Semi-Permanent Hair Dye?

Semi-Permanent Hair Dye allows you to colour your hair for a short period of time and much less commitment than a permanent. If you’re looking to try out a new colour, or simply want to change your look often, semi-permanent colour is a great choice! You can use Crazy Color directly from the bottle to achieve a single colour – there are 40 shades to choose from! But the fun really starts once you start mixing colours to create your own completely unique shade. As it typically lasts 10-12 washes, you can be as experimental and as crazy as you like! If you find a colour that you love and want it to be your signature look, you can continue to top it up using our tips and tricks! Find out more here.

To achieve optimal results, we typically recommend that you pre-lighten your hair to level 9 or 10 (blonde). Our products will also work on hair at level 8 (light brown), although the results will be tonal.

Crazy Color Semi-Permanent Hair Dye is completely free from ammonia and peroxide, so it is a healthy and non-damaging way of adding colour to your hair!

Semi Permanent Dye Guide
Semi Permanent Dye Guide
Semi Permanent Dye Guide

How Long Does Semi-Permanent Hair Last?

Our Semi-Permanent colour will last approximately 10-12 washes. However, the longevity of the colour will vary from person to person based on the overall health of your hair and its porosity. 

The colour will be at its most vibrant as soon as you’ve finished the application process, and over time it will gradually fade. Each time you wash your hair, the colour will fade a little bit more. However, this is part of the process and your hair will still look great as it starts to fade! In fact some of our shades are picked specifically because they look beautiful during the inevitable fade! Prolonging the life of your vivid hair is also highly dependent on your aftercare routine, so have a look at our tips on how to nourish and hydrate your coloured hair. Please note, colours such as blue and green can be more stubborn and will typically take a little bit more time to fade. 

How Does Semi-Permanent Hair Dye Work?

Unlike permanent products, semi-permanent hair dye does not penetrate the hair shaft to change its base colour. Instead, it coats the outer surface of the hair which is a damage-free process. Colour particles cover the outer layer of the hair shaft, without affecting your natural pigment. These colour particles are so small that they will eventually be removed from the hair after washing it with shampoo (10-12 washes). Crazy Color Semi-Permanent Hair Dye has been created using a gentle conditioning formula that will leave your hair nourished and hydrated.

This temporary method of dyeing your hair opens up lots of exciting options and gives you the flexibility to change your hair colour as often as you like!

If you’re like us, you love the variation offered by semi-permanent hair colour. You can continually experiment with new colours by mixing any of our 40 shades to make a colour you can call your own.

Does Semi-Permanent Colour Damage Hair?

As it is completely ammonia-free and doesn’t use harsh chemicals, semi-permanent hair dye will not damage your hair. One of the main reasons for this is that it does not compromise the hair shaft. It simply coats the surface of the hair which means the colour will wash out over time. Our formulations are ammonia-free for this reason, we want what you want: super hydrated, healthy colour with optimal vibrancy and shine!


We are proud to produce PETA approved, 100% cruelty free, award-winning vegan hair dye and colour care products. We are strong advocates of ethical production & testing, and this is something we have always been completely  committed to. 

Will Semi-Permanent Dye Stain my Hair?

Semi-permanent hair dye will not stain your hair and it will completely wash out after the appropriate number of washes (approx. 10-12). Semi-Permanent hair dye does not compromise the hair strand, it only coats the outer shaft. This means that given adequate time and washes, the colour should be completely removed from your hair. However, there are factors that can contribute to colour being more stubborn to leave your hair: if your hair has been dyed repeatedly, if your hair is exceptionally porous, if your hair is dry and damaged or if your hair has been over-bleached you may notice it takes longer for the colour to leave your hair. Check out our pro tips on how to remove semi-permanent hair dye.

Is Semi-Permanent Hair Colour Safe to Use During Pregnancy?

Yes, it is safe to use semi-permanent hair dye while you’re pregnant, as long as you are cautious throughout the application process. The chemicals which are used to produce semi-permanent colour are not considered to be highly toxic and research confirms that it is safe to add colour to your hair while pregnant. Semi-permanent hair dye will only coat the hair strands and will not be absorbed by the scalp at any point. 


Before you start your DIY-Dyeing session, we suggest that you should carry out a Strand Test and then go for it, following our How To Guide


Please note, this is not medical advice and should only provide general direction. All medical concerns should be discussed with your doctor.