For awhile now I've been wanting to do this with my hair and I've finally decided to get it done. I have dark brown hair. I would like to have it jet black with blue lowlights mixed in. I don't want a bright blue... I want the blue to be very dark. I don't want it to look very drastic... just kind of like a tint to the black hair. But also obviously something that can be seen or else it would be pointless.
My question is... do I have to bleach my hair for the blue? Or is there anything special that I need to have done for that? I'm having it done professionally, so I'm sure they will know but I thought I'd ask and do some research before going in. I'd love to cut down cost and do it myself but my hair is very thick and wavy and long and I never attempt to dye my own hair lol

If you want only very very faint blue highlights then you can try to go over the black but there is no guarantee it will work.

I had my hair dyed black with bright blue highlights a while back (doing it again tomorrow actually)

What I did was to first bleach the sections I wanted to turn out bright blue...
I then wrapped those sections in foil so that they were completely covered.
Then I applied the black dye to the rest of my hair...
Wash out the black dye in the shower and remove the foils
Then you can apply what ever color you like to the bleached sections.


Now for a very dark blue you may even want to consider trying a blue/black dye.
These dyes look black until you stand out in the sun, then they have a slight blue tinge.

In that case then you will not need to bleach.

Just wrap the sections of hair you want to turn out blue with the foil and dye the rest black.
When you rinse then you can use the blue/black over the brown hair left over.

Since your hair is a brown, dying your hair blue without bleaching it to the correct shade will probably cause it to become a turquoise and then fade to a gross green.

Blue is the most difficult of unusual hair colors to dye to so it does take a lot of work and maintenance. When bleaching brown hair it will turn a very brassy red to orange to yellow. In order for the correct blue to show you'd need to have it an almost white, to pure white platinum hair.

That should be done by a professional because bleaching your hair is ridiculously damaging if you have dark thick hair. (I would know because I bleached my jet black thick asian hair to a platinum white) Make sure that they don't dye your hair blue until they make it to the correct shade.

As for getting to the subtle blue, use the darkest blue you can find. Here is one that might be good. Manic Panic is heard to be fantastic.
Manic Panic - Manic Panic After Midnight Blue (http://www.sallybeauty.com/midnight-blue-hair-dye/SBS-484010,default,pd.html)

That is something you could do yourself or with a friend and it is not very damaging or not damaging at all. Just be careful!

For black, make sure to do this AFTER bleaching your hair because it is the most difficult color to take away from the cuticle since it IS the darkest color. Though I do this myself (because I intend on being a hairstylist, maybe) and I know what I'm doing, I wouldn't suggest doing this yourself because it IS permanent and messy. Tell the stylist exactly what parts you want done because once it's done, it will most likely be permanent unless you want damaged beyond repair hair.

I don't know if I missed anything or I said too much or maybe just the wrong thing in general but if you need help just contact me!