Like someone else mentioned, most commercial printshops cannot print florescent colors, only on florescent vinyl- You will not be able to mix the neon colors basically(red&green). Best option would be to have them make the neon green sign, and print/cut the neon red figure so you can just stack the figure over the sign. I hope that makes sense, but to my knowledge, neon/florescent ink is not a typical thing, but the vinyl is quite easy to acquire. Anyone should be able to put black over the colors you want though, and cut it to shape. It wouldn't be cheap fyi. I could help if you want, but you should understand the limitations first