You're better off using purple hair dye or blue dye over green hair to really counteract the green and give you a new purple shade or hue.
Red: Since green is opposite red on the color wheel, using a red dye can help counteract the green. This can be a vibrant red or a warm auburn. Copper or Orange: These shades can also effectively neutralize green tones, as they contain red and yellow undertones.
Red or Copper: Since green is opposite red on the color wheel, using a red or copper dye can help neutralize the green. A deep red or a vibrant copper can provide good coverage.
Green sits opposite of red on the color wheel, so when it's safe to color your hair again (wait at least two weeks), look for a warm brunette shade with reddish or golden undertones.
Color Correction Techniques:
One effective method is using a red-based color to neutralize the green. Applying a warm-toned dye can counteract the unwanted hue and restore your hair to a more natural shade.
Taking out that green tint couldn't be simpler — it won't even take you 5 minutes! After shampooing, apply Pink Toning Conditioner to your wet hair. Be sure it's evenly distributed throughout your hair, and wait 2-3 minutes. After that, all you need to do is rinse and dry!
If you're trying to neutralize or tone out a shade, use the one directly opposite on the color wheel! In this case, pink and red tones will tone green. Pink Toning Conditioner is a red-leaning pink designed to take care of green and even teal tints!
In many cases, your light blonde hair may turn unnaturally gray, or even green, if you try to put brown dye on it. This is especially true if you are going more than two shades darker.
If we look at red, the color opposing it is green. When red and green are combined, they neutralize each other (i.e. cancel each other out).
Generally speaking though, it's best to wait 4-6 weeks before having another color treatment – in most cases, this is enough anyway and reduces the risk of hair damage. There are some exceptions, but in general, it's better to err on the side of caution and wait for this long.
A baking soda wash can be a first line of defense against green hues. Simply create a paste by mixing baking soda with water. Apply this mixture to wet hair, concentrating on the green-tinted areas.
Purple shampoo can effectively neutralize green tones in hair, particularly after swimming in chlorinated pools. The shampoo's purple hue counteracts the green on the color wheel, effectively cancelling it out.
When you mix red and green, it may seem logical to assume that you'd get some sort of “Christmas color,” but that's not the case. Instead, their unique pairing creates a new and unexpected hue – brown! That's right, mixing the two primary colors of red and green together results in a warm and earthy brown color.
Heat opens the cuticle, which is the layer surrounding the hair fibre and is where the pigment hides. This'll help stubborn dye to leak out. Blue or green staining won't disappear in a few washes, though. It takes time, so enjoy all the different colour changes it goes through.
Jet Black. When in doubt, black hair dye will always cover green—but beware, it's a commitment!
A red color will cancel out the green but since it's teal you'll want to get an orange based red. Then you could go ahead and use a hair dye that's your color to match better with the rest of your hair. If you're trying to color the ends red then I'd second what Alyx said about using dish soap.
The green should be neutralized with the color that is opposite it on the color wheel—red.
Red is the colour opposite green on the colour wheel. This makes it the colour most in contrast with green.
Magenta absorbs its complementary color - green. Thus, green is subtracted from white light.
But can you believe it: IT WORKED! I generously smeared and combed the ketchup into my ends, wound my hair into a bun, gave my girls their bath for 20 minutes or so, then shampooed/conditioned, and just like that, the green slime was gone. My blond streaks were back and intact.
If you have little or no heat in your hair, an ash shade can make it look green. An ash shade contains a little blue pigment that counteracts the heat in the hair. If you have little or no warm pigments in your hair, the ash colour can give your hair a green tint.
To get rid of the pool green, thoroughly saturate hair with lemon juice (either fresh or bottled). Let sit for several minutes before rinsing, washing, and deep conditioning.
Words of warning - take it from me if you are thinking of using your own purple shampoo to combat that green, ashy hair. It has the opposite effect and will do nothing to help beat the green. Don't waste your precious purple shampoo on the green hair curse. It will NOT work.