Oh yeah, one last thought I forgot to mention. I have used "Ritz Dye" in the past to dye plastics. It is actually a fabric dye found at most grocery stores, maybe $2. You mix it with water and dip your plastic in it, but I think you could just soak a cloth and wipe the screen with it. Let it soak in 5 minutes and wipe off. I'm pretty sure it's available in shades of gray. You have a lot of 11" cut-off pieces to experiment with... (wear plastic gloves!)
Again, I'm a "newbie", and read something about gray screens, thought I'd throw that out there.