I'm not aware of any... know anyone that works at a body and paint shop? Wouldn't be too hard to decase a typical keyboard and scuff and spray the case... it could look really nice. I'm thinking a candy green Imron with maybe a base layer of copper or gold flake underneath, then clearcoat over the whole mess. PIMP! I'd do it for you if I had a good workspace... I love that kind of stuff. (yes, I do have my own HVLP setup and both a spray gun and a cheap jamb gun, which would probably be better for this kind of thing.)
You can probably get results 99% as good if you just disassemble it, clean thoroughly, and use a paint or dye intended for plastics in a spray bomb. Seriously, I've done some decent work with a spray can... half the driver's side of my old GTI was painted with black spray cans
(I don't miss being broke, but it was a good skill builder.) If you're not used to painting though, it'd probably be a good idea to practice on something first...
I don't have a Filco but the pics I've seen online make it seem like the case has a little texture to it. The WASD case is almost smooth and would require less surface prep to lay down a nice coat of paint. I haven't really looked to closely at other keyboards, those were the two that I had to decide between when purchasing a "good" board.
If you REALLY wanted to pimp it you could leave the case black but spray the plate for the switches green, a la TypeNow Solid. But to do that you'd have to either spend all day masking around each switch, or desolder all the switches and remove them, then spray the plate, then reassemble. Might not be worth it :/
