If you still look like you do in your userpic it looks like your hair is natural. It's going to be a pain in the butt if you want to dye your hair green. Just remember that you will have to bleach it first if you really want the color to show. Since your hair is long it could take you years to grow back healthy hair after damaging it from the bleaching. But if you still want to go for it I like the wildberry. I used to keep my hair dyed fire engine red then finally I got sick of it and ended up buzzing off all my hair since it was the easiest way to just start over.
When I was 16 I wanted to dye my hair blue. So I went and got 2 boxes of hair bleach first and also 2 things of blue (royal bright blue) dye.
Well, I have really long, dark hair like you and BOY was I stupid to even THINK that it would turn out ANYTHING like I wanted, or anything like the pictures you have up there. The 2 boxes of bleach did nothing but turn my hair really light brown/ dark blonde, which does NOT cut it if you are trying to bleach your hair a really bright primary color like that. You seriously have to go close to platinum blonde first and then dye your hair whichever color you want for the color to look anywhere CLOSE to blue or green or whatever. Then after I bleached it, I dyed it with TWO freaking things of blue dye.....well......I tell you what.....I turned out having SILVERY LIGHT SEAFOAM GREEN HAIR after that. So a couple of months later I dyed it red, then red and black and then finally I dyed it back to brown.
It seriously took like 2 or 3 years for my hair to recover from the bleaching.....
Just to let you know Buuuut, we all have to learn the hard way on some things I suppose!
I also wanted to add that if you are really serious about dying your hair that color I would go to a professional, it will be expensive but worth it. As silver explained it's not as easy as it seems. Since you have such long beautiful hair it would be worth the money to have someone do it right.