Blue Semi-Permanent Hair Dye

Blue semi-permanent hair dye that will actually show

Blue is the strongest pigment we make and the fussiest about what it goes on top of. Three blues are buyable at the moment and they behave differently, so here is what each one does and where each one falls down.

Royal blue and electric blue hair dye, open to pre-order

Royal Blue and Coral Blue have both come back in new 100ml tubes with new photography. The formula hasn't changed, only the packaging and the size. You can order either one today and it ships in late October. Royal Blue is the deeper of the two, a dense ink blue that keeps its depth as it wears down. Coral Blue is the electric one, close to a neon, and it's the shade to pick if you want blue that reads bright from across a room.

Neon Turquoise: UV teal hair dye, in stock

Neon Turquoise ships straight away. It's a bright teal sitting between blue and green, and it's UV reactive, so it lifts under blacklight at a club or a festival. On a pale base it comes out clean and almost tropical. On anything darker it turns green rather than turquoise, which some people are after and some people very much are not, so do a strand test before you commit.

What your hair has to be before blue hair dye will show

Blue needs a light base. On dark brown or black hair none of these three will read as blue. You'll get a faint cool cast in bright sunlight and not much else. To get the colour on the tube you want hair lightened to a pale yellow first, and our hair bleach kits will take you there. One thing we say on every product page and will keep saying here: our semi-permanent dyes do not cover white or grey hair. If that's what you need, this isn't the range for it.

How long blue hair dye lasts and how it fades

On hair that hasn't been bleached you'll get roughly five to seven washes. On pre-lightened hair it's closer to fifteen. Blue is the most stubborn colour we make, because the pigment molecules are small and sit deep in the hair shaft. That's good news while you want it and less good news when you want it gone. It fades towards a green-blue rather than washing out evenly, so plan your next colour around that. Cool water and a sulphate-free shampoo buy you several extra washes.

Getting to navy, teal or something deeper

We don't sell a navy on its own, but you can build one. Stargazer colours blend with each other, so Royal Blue with a small amount of Violet gives you a cooler, deeper blue than either on its own. For a true teal, work Coral Blue into Neon Turquoise until it stops leaning green. There's no peroxide or developer involved, so mixing is just mixing. Wear gloves, and strand test first, every time.

If blue isn't quite it, the purple semi-permanent hair dye range sits next to it on the colour wheel, and the pink hair dye range goes the other way. Everything we currently have is in the full semi-permanent hair dye range, and every one of those dyes is vegan, which you can see for yourself in the vegan hair dye collection.