How to make rainbow hair dye last – DIY rainbow dye guide

rainbow hair dye


Rainbow hair that lasts for months? Yes please. Malin shares her DIY dye tips for a non-smudge look that stays put!

Lovely locks in every shade of the rainbow can do wonders for one’s style, and few things make me as happy as freshly dyed hair. But it can be so hard to keep it vivid and bright. Also, re-dyeing all the time is expensive and not all that fun.

While I (disclaimer, disclaimer!) am not a hair care professional and have had no formal training, what I do have is 13 years of experience in dyeing hair for myself and my friends. Brace yourselves for some tips and tricks I’ve learned on my colourful journey so far!

rainbow hair

Rainbow hair, coming up! What colours will you choose?

Rainbow hair needs love and preparation

Some people speak of hair-dye days. I speak of weeks, or even months. How long you need to start preparing depends on your hair; its type, colour, and whether it’s already dyed. Beware of henna – it can mess up some other treatments.

Bleaching is important; it not only lightens hair, but makes it more susceptible to dye. Don’t skip it, no matter what colour you’re starting from!

Light hair: I, being the whitest person in the world as I am, with stereotypically Swedish blonde manageable hair, can do one simple bleach treatment and then I’m good to go. If your hair is like mine, just pick the weakest bleach you can find for anything but pastel shades (that’s a medium bleach, plus a toner treatment or two).

Fair hair: Hair lighter than dark brown rarely needs stronger bleach than medium for most shades of hair dye.

Dark hair: Darker hair might need stronger bleach.  If the colour you want to dye your hair is light in shade, and your hair is very dark, you might need two or even three bleach treatments before dyeing. In that case, wait at least 2-3 weeks between treatments, and consider a bleach bath, as it is easier on the hair. This is imperative, as bleach can be very damaging.

If bleaching turns your hair orange: consider a toner treatment (a slight bit of purple dye mixed in with conditioner) to neutralize it before bleaching again. Never attempt to dye it white using only bleach, you will fry it! And fried hair is never going to be in fashion, darling.

2-3 days before the dyeing is to take place, wash your hair with shampoo only. Don’t condition, as conditioner is acidic and will close the hair, making it less susceptible to dye. After you’ve cleaned your hair with shampoo, don’t use any hair products until dyeing. This is due to a slightly greasy scalp being better protected from the bleach.

After that pesky bleaching is all done, on to the dyeing!

D(ye) Day is here!

So it’s the day we’ve all been waiting for! The day you dye your hair.

Start, as previously mentioned, with bleach. Follow the packet instructions, wash it out, let it dry, and don’t use the aftercare treatment. Brush your hair and make sure it is evenly bleached.

Tips for dyeing bright hair in one colour all over

When dyeing hair a uniform colour, a good rule of thumb for creating depth and dimension to hair is to use high and/or lowlights. Pick one shade to be the main colour, and then at least one more of a distinctly different but close shade. Mix a few tablespoons from both of them together to get a third. Even better, buy three dyes and mix them up to get  shades. Then use the extra shades to make high-and/or lowlights in the hair. Oh, so pretty!

Rainbow hair dye tips

rainbow hair dye

I think I had 6 different shades in my hair here. And also an entire garden, apparently.

Your choice of rainbow hair colours (yeah, you know you want it!) will of course get mixed up while the dyeing is in process if they touch. So dye sections one by one. Twist each section up, as if you were making pincurls. Pin or clip them to your scalp. Finally, if necessary, put aluminium foil on top of them to avoid touching with other dyes.

Keeping your rainbow hair colours separate for as long as possible

Unfortunately, the colours of rainbow hair dyed in the way I described above will always bleed into each other when the hair is eventually washed. In order to make them look separate and not like a muddied mess for as long as possible, pay attention to the placement of the dyes. Here’s how:

A darker colour placed on top of a lighter one (like an ombre that goes from black to pink) will likely affect the lighter colour a lot. On the other hand, a lighter colour can often bleed into a darker without too much awfulness ensuing.

Ya got all of that? Good, because now the difficult part is over (phew!) and you’re now in for a whole lot of waiting.

First, put on a shower cap. As long as the dye is wet, it will continue processing, and the cap also protects everything around you from the dye.

Keep that rainbow hair dye in for as long as you can wait. Preferably overnight. Ignore the laughable 15-minutes instructions on some brands’ packages – the longer the better, and most modern dyes are actually nourishing for the hair, so don’t worry.

When the processing time is done, rinse your hair with white vinegar. This helps because white vinegar is very acidic, and will therefore close the hair and seal the dye in). After your white vinegar rinse, rinse the dye out in water as cold as you can manage. Then spoil your hair with hair masks, deep treatments, whatever you want. You and your hair have deserved it!

Keepin’ it real(-ly colourful)

My top tip for keeping your dyed hair from fading is, of course, not to wash it. And if washing is still done, not to condition.

Of course, this isn’t really possible with all hair types and hairstyles – but if you can cut down on the washing, do. And choose colour-preserving shampoos, conditioners and hair masks.

For hair dyed in different colours, you may want to make the different sections large enough that they can be washed separately, if you don’t find it too time-consuming.

Another smart thing is to put a little bit of your dye in your shampoo and/or conditioner bottle. That way, you get a little bit of a colour top-up every time you wash it.

rainbow hair split dye

This split dye lasted 3 months with no re-dyeing and the colours didn’t bleed into each other at all.

If you’ve followed all these tips correctly, I’m sure you will have amazing hair by now, and it’ll hopefully last for weeks, or even months.

Go out and be fab, and be it forever!