It is the same lighting as the climate controls, i.e. the white writing is "backlit" and has a greenish color in the dark when you turn the headlights on. If I push the rear defrost button, there is the small slit which turns red, which still works fine. They just can't be seen at night, I know where they are, but if someone else is driving, they can't find them.
I went by the dealer today to let them "take a look", they said I would have to remove the entire center piece of the console and door panels, respectively, to replace the bulbs. Estimated in the neighborhood of $125-150, they said probably not worth the money unless I just can't live without it, or if I could do it myself.