I work for an automotive paint manufacturer and this sounds like Translucent White Paint (It actually looks like a very light blue) under a black coating (although you obviously wouldn't be using the black) . In my opinion the best way to do that is to Mask off the non-painted area and then just pull the masking off when done painting, the Translucent White should have enough light transmission value to give you that look. The only problem is I don't know where you would get that type of paint, although I think you could find it by doing a internet search (Google is your friend
). Next time you get in your car at night look at your lighted controls and you'll see what I'm talking about.