Ebony black over greenish blue

Who told you that nothing would take over the green, and do you know why they thought this? What green dye did you use?

A red based black should technically take over the green and the blonde, though it may fade differently over different areas (even if you use a 'permanent' black it will fade over previously bleached hair). You may need to do a bleach bath on the parts that are your natural hair if you are using a direct dye to allow it to stick better as they have trouble adhering to virgin hair, but if you are using a permanent black dye this won't matter.

As always I'd recommend a strand test on areas that have the different colours in to see what you'll end up with before you take the plunge.

I used Directions Atlantic blue, and also Apple Green on some spots though this one is completely gone I believe, my hair are really just turquoise now.
I went to a hair salon and showed my hair and the guy was so shocked he said "nothing will hold over the green, or faded blue. You have to bleach it first" It sounded quite silly to me, plus I don't really want to pay 80$ and damage my hair any further.
I don't know if I feel confident enough to bleach my hair at home, plus I don't know how to do a bleach bath or anything.
I'm ready to try a permanent black dye but then I want to be sure it will hold well.
Is Ebony black red-based? Because if it is I have a chance to "cancel out" the greenish in my hair. And just to be sure: if I use a dye labeled as "permanent", it will hold without me having to bleach my natural colour but it will still fade on what is bleached?

Ok, so I think he meant that the green and blue will show through as your new colour fades, I think many salons aren't used to dealing with direct dyes and bright colours so they panic a bit.

You will be able to counteract the colour that is already in your hair by using red or orange depending on how green or turquoise it is. It might be best to use something in a directions dye first to do this as direct dyes are the pure colour they show on the swatch where as a black permanent dye will be meant for use over brown hair and might show up unwanted tones.

I recently changed my hair from very bright red to mahogany brown and this is what I did:

Dyed it with a mix of Adore and Directions which included some turquoise to cancel out the red/ orange.

Then dyed it with a permanent brown dye which took care of my roots

Then I keep it topped up by using Adore direct dyes every few weeks when the permanent dye fades on the ends where there used to be bleach.

I then just do my roots with the brown permanent dye when they come through to give the adore something to help it stick.

If you intend to keep your hair black afterwards then this may be a good plan for you, but if you intend to change your colour again in the future it will be worth learning to do a bleach bath and then just using an adore black.

I can't really answer whether Ebony is a red based black as different brands use different descriptions and names.

Here is what my hair looks like now. Should I go for a Poppy red, Fire red / or something darker like Vermillion and Pillarbox? Or maybe something more orange like Coral red and Tangerine? And what will a red dye look like over the blue? (cause really I don't want to end up with weird muddy brown hair)
I'm sorry for asking a lot but I really have no idea which colour will work out the best.

Also, I don't know the accuracy of this but I read that permanent dark dyes were pretty aggressive and could result in itching or even "burning-like" reactions. Therefore, I'd rather do it in a salon (also because I'd like a nice transition from my natural hair color, so that I don't necessarily have to do my roots as soon as they appear, but maybe let the black and have nice transition that would not be too harsh) but I'm afraid the guy won't agree to do it if my hair isn't bleached before... I'm not really sure what to do.

If I was to do it at home, is Manic Panic permanent, or do you have any brand you would recommend?

Thanks a lot!

Ok, so there's quite a lot of blonde there, I was expecting it to be much greener than that. If you do use a red or orange to neutralise it, it will turn brown - that's what neutralising does unless it's a case of very pastel tones on very pale blonde hair. It will also turn red over the blonde parts.

The itching and burning with dark dyes refers to PPD allergies which are possible with any chemical based dye (other than direct dyes that state that they don't contain them). These are the main reason that you always need to do a sensitivity test before every time you use a hair dye, often hairdressers don't insist on doing a test so it can actually be more dangerous to have it done at a salon. If it is something that concerns you then you need to make sure the salon do the sensitivity test for you.

Personally I would try another salon and get another quote if you really want to get it done professionally. I have had colour corrections done in the past at salons from lighter to darker but they have been two stage processes with a semi permanent filler colour and then a permanent dark colour over that.

No, Manic Panic is a direct dye - it will go over the bleached and green bits but won't stick to your roots for very long. 

Okay, I will probably choose the Pillarbox red which is not too bright, to make sure I end up with a rather dark colour.

I promise it's the last question ^^ : How long should I wait between doing the red dye and doing the permanent black dye?

Directions Pillarbox has come out really bright when I've used it! You could dilute it in conditioner and apply it over the green in a strand test to see what happens.

Are you going to be doing it yourself? If so you don't really need to wait long between doing the direct dye and the permanent - just don't do it the same day as it's better to use permanent dyes on hair that is not too clean.

If you are still thinking of having it done at the salon I would still advise going and getting a second opinion from another stylist as if you cover up the green first they won't have a true idea of what they are dealing with underneath.

I'm not sure I understood fully about how you wanted it so your roots wouldn't be noticeable but if you meant that you want some kind of brown to black ombre I would suggest you could try adore browns and blacks over what you have now. (direct dyes).