Green screen face mask? Or paint?
 

The deal is that I want to have some kind of chroma key effect on a person's face. Every part of them except their face will be shown, including their hair and neck. I took a look and didn't turn up much for a green screen mask, so maybe there's some kind of paint that will work well?

What about the eyes?

Anyhow, one thing I was thinking of would be something called "Clown White" which is as you might expect is what the clowns wear. Then pretend you're doing a "White Screen". Not sure if it would work or not, but maybe worth a try.

If you do go this route, though, DO NOT FORGET to also get Clown White remover. I had a friend who painted himself with clown white for his kid's birthday party on a Friday and then discovered that nothing short of sandpaper would take it off and he had to wait until Monday when the store opened up again.

Anyhow, just a wild idea FWIW

preface i dont know, most of the green screen we did was not for "effects" as much as just changing the background.

saw in the movie stuff that they would just drop a bag over thier head, made of the exact same materials as the green screen itself, no guessing.

if i was to whip out something quick (that never works) to qualify under your specs for what you want to cut, i would find a old simple haloween plastic mask (Craft store off season), cut out the parts needed and not, then paste a green screen fabric (of the same as my screen) onto the mask covering the eyes nose and mouth too at the same time, onto the mask.
of course set it up so they can still breathe through the fabric, so if your using some plastic stuff i wont be liable for killing anyone, just trying to help.

I thought about the bag over the head, but then I saw that the OP wanted to keep the neck and hair - hmmm

Check out Cinema Secrets. They make facepaint in all different colors. Then just use the facepaint to color in the parts you want to chroma key out of your production.

So now I am editing the post. THis would be even better because it's likely a lot cheaper of an option. Hopefully I am allowed to post web links. Heres one for face painting artists. They use this a lot at kids parties.

https://www.artisticfacepainting.com...ce-paints.html