Well, it sounds like your hair is already damaged, which is why it isn't holding any pigment when you try to colour over it. So I would not, under any circumstances, try to bleach the green out. It's not going to work anyway. It'll damage your hair, dry it out, make it even less likely to hold colour and your hair will still have a green tint.
What I'd recommend is to get a good deep conditioner with protein in it. If you go to Sally's, they can recommend a good one for you. I've heard that the one by Aphogee is incredible, but I haven't tried it personally. You need to get your hair in better shape so that it will begin to hold pigment again.
What's happened is this: whenever you use a haircolour with a developer of 20 or more, a relaxer, or a perm, those chemicals change the pH of your hair. Your hair, skin and nails have a slightly acidic 4.5 pH, but when you use those chemicals, they will bring your pH to an alkaline level in order to coax your cuticle to open up so that the cortex can be penetrated. This is where the protein of the hair is stored. So when you use chemicals that are strong like this, sometimes they can cause your cuticle to become "stuck open," for lack of a better term, and unable to hold onto pigment because the molecules slip out through the open cuticles. So your first priority should be repairing your hair as much as possible.
It's important to add proteins back into your hair to give it strength and keep it from breaking. But bear in mind that too much protein can also cause the hair to become brittle and break MORE....catch 22, right? haha! So I like to use a protein deep conditioner, rinse, and then immediately follow with a good moisturizing conditioner. You need a balance of protein and moisture. Keep repeating this conditioning cycle at least once a week, if not twice, and you will begin to see improvements in your hair.
Next, we tackle the colour. With colour, it's best to consult the infamous colour wheel
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[email protected] 2x" width="20" height="20" /> First, you find the dominant pigment you're seeing in your hair, which is green. Then we look across the wheel to see what the opposite shade is, which is red. This means that red will neutralize the green. This is why your hairdresser used red-based browns to try and even your tone out. If you use a neutral brown or an ash brown, you will 100% have green tones throughout your hair regardless of how dark you go. You need to add the red back in to bring it back to a neutral shade. Neutral, by definition, is a 50/50 mixture of warm and cool, right? So you've got your cool...now you need to add your warm back in. And since your hair sounds a bit damaged, I'd recommend a demi-permanent to start off.
Demi-permanent dye has a 10-volume developer, so it will not lift your base shade, but it will open the cuticle enough to penetrate the hair shaft just enough to deposit pigment. Now, bear in mind that your hair isn't holding pigment well at the moment, so you will wind up having to colour your hair relatively often until your hair starts to build back up and accept the colour again. So this is another reason a demi-permanent will be your friend. And you could even alternate between a demi- and a semi-. Semi-permanent deposits colour also, but uses no developer, so it does not penetrate the hair shaft, it merely stains the outer cuticle.
So what I'd do is find a nice medium-to-dark brown (level 4 or 5) with a red undertone and do a demi-permanent first. Then once you've reached a shade you can live with, start with the semi-permanents if you start to notice your hair isn't holding onto the colour. Just wash your hair really well, apply straight from the bottle to your hair (no developer), wrap your hair up in a cap (make sure to drape your shoulders with a towel and use gloves because semis are a big thin and runny), process and rinse. It'll fade with each shampoo, but it's the least damaging of all the hair colours, so it'll be the healthiest way to keep depositing colour while saving yourself some damage.
Good luck with everything and if I can help more, please let me know!
