I recently dyed my hair golden blonde to a medium natural brown and at the ends it turned green! My natural hair color is the medium natural brown. How do I get rid of the green without dying it again? Please help.
I was a cosmetologist and color was one of my fortes; what has happened here is you chose a brown with an ash base. Additionally if the ends turned green they are extremely damaged or porous, and have grabbed the base color from the hair tint you used. There's nothing that can really be done that would last on your ends to correct the issue, because they won't hold color correctly for long. A temporary fix would be to purchase a reddish color like a light auburn or strawberry blonde or similar in a semi-permanent color like Clairol Jazzing, and color just the ends to neutralize the green. But, because the ends are damaged it will not last as long as it is supposed to, and you will have to do it frequently.
You could also use a permanent color in a medium tone which contains red as well, but that will only make the damage worse. Your best bet outside of seeking a professional stylist would be to use a reconstructor and a moisturizer, trim off as much of the damage as you can, and correct any leftover green with a reddish color at the ends.
Don't worry, the green won't turn red, the green will just be neutralized. Realistically, I wish I could tell you a good trim isn't needed, but in this case since the green took at the ends, that tells me the ends are somewhat beyond a permanent fix. Unless you do not like golden or reddish tones in your hair color, never choose a 'natural', 'neutral', or 'ash' hair color, always get a 'golden' color, or a red undertone like an auburn or something.
A little color theory: red neutralizes green, just as those violet shampoos neutralize yellow in a head of white hair. They cancel one another out. Good luck, and in the future trim more often; doesn't have to be a whole lot of hair trimmed, just often enough to prevent this damage.