Hey! Your helmet looks great! Just a quick suggestion since it's the EVA helmet that you're working on.
I've been looking into visors and other than motorcycle visors, there isn't to much reference to other methods.
*Granted, they're cheaper. But they give the desired effect.
What I plan on doing for my helmet (It's the reach scout helmet) since the visor is so minimalistic is just to get some colored plastic sheet (In this case, blue), mirrored window film, and two plastic bottles cut open for the visor. I just glue them together like a sandwich, and then detail them according to some post I found stickied somewhere.
But EVA is kinda hard cause it's like 50% of the helmet.
Idk where I found it, but basically it's called vacuforming.
You should look into it. Solidfy the paper visor and then vacuform it. You should get nice results.
*Just what I would do. I haven't done it before, but since I know that it's a way, I figure I should let you know.
Vid I found online:
Tutorial for doing it yourself at home:
^Just realized that this video doesn't actually teach you how to do it.
This is the link for that:
http://www.instructables.com/id/Make-a-good,-cheap,-upgradeable-sheet-plastic-vacu/