Looking for a long lasting blue dye

Directions Turquoise generally lasts a looooong time. It's permanent for some people. I've been told Manic Panic Atomic Turquoise has recently been changed and also is permanent for some people.

I like adore aquamarine.
If you want totally permanent, there is Ion. Their blues don't ever come out.

Seconding aquamarine, it's a fab colour and super long lasting, even when diluted.

Hi, thanks for all the suggestions. Where do you usually get Ion hair colour from?

I've seen it in Sally's and on amazon. Do remember though, you have to be sure you want it permanent. There's no bleaching that stuff our from what I hear.

I don't see Ion colour brilliance on Sally's UK site, only Ion colour flash which I'm not sure is the same thing.

They don't have it on the website, but stock it in some stores (or did, i haven't seen it for a while) The Colour Flash is a different line entirely
There are lots of blue dyes that will last for several months, but that will still come out if you ever want to change colour. Ions blues need to grow out or be cut off, they are more permanent than permanent dyes

Is there no way to remove Ion blue but to cut your hair off? It's not that I wanted permanent blue hair but it would be nice to have a persistent blue that only come out when I no longer want it, and then I could remove it with a colour remover of some sort. Because I usually go swimming and especially during summer, the ocean water and the sun from my country (vietnam) is too harsh, plus I don't want to wear a swimcap if I could avoid it.

If you ever want to get away from blue I would avoid Ion.
Adore aquamarine will last a long time, so do the Special Effects blues (most of them are purple based rather than turquoise though) Pravana blue.  Arctic fox is also supposed to be long lasting (it is new and I haven't tried it)
Directions turquoise (or atlantic blue) will last a lot longer than lagoon Blue

I like adore aquamarine...

Seconding aquamarine, it's a fab colour and super long lasting, even when diluted.

Thirding! lol very long lasting and a lovely colour.

I already bought Adore Aquamarine and it arrived today.  *thx* *thx* *thx*