Brighter lighting

Foil Duct Tape. Sticks where you put it, highly reflective.

Brighter lighting for what? Inside a passenger car, overhead lighting of a room?

I've been meaning to put this to a test, but, haven't gotten around to it yet. However, I'm willing to bet a dollar to a dozen doughnuts that using white will give you better lighting than foil and a hundred times better than a mirror. White will diffuse the light where foil or a mirror will tend to reflect only the single source of light.

Other than headlights, was prototypical lighting really bright inside trains?

I kinda like the low glow of interior lighting over something that resembles an operating room.  Inside buildings and passenger cars I like enough light to just see what's inside, not something that looks like a blast from an atomic bomb.

I even like the warm glow of of a headlight of my steamers over the bright beacons I've seen on my diesels.