I have my headlights LIGHTLY smoked with niteshades. I did them darker on the sides to hide the orange a little better during the day and blend with the car.
It still shines through just fine.
I tinted my headlights and my tail lights. I figure if some cars come stock with the tinted headlights, and tail lights for that matter (Grand Am GT's for example) that it wouldn't be at all illegal to have mine as dark as their's (remember laws state how far away the lights and reflectors can be seen.) Just keep it light. AND Clearcoat them after they have had plenty of time to dry (so it looks shiny and keeps it looking stock.)
Here is a picture of mine.
*edit* Just a note. The tint has made a VERY small difference in the headlight brightness (not enough to not drive at night with them). I think If I had silverstars that it would go good with this mod.