Do these lights still function after the smoke finish is applied?

Yes. The smoke finish reduces light output visibility from certain angles but does not prevent the lights from working. They're street-legal and perform their original function.

Will I need to remove the factory lights to install these?

You'll need to disconnect the factory assemblies at their mounting points, then secure the new smoke lights using the same factory holes. No drilling or welding involved.

Can these be painted or modified after purchase?

The smoke finish is pre-applied. If you want a different color or finish, you can sand and repaint the housings with automotive paint, though the lenses should be masked off to maintain clarity.