I proposed on a beach at night, and I used a lighted ring box. It had a white light in it, and it was perfect! I spent a lot of time picking out her ring, so I wanted her to be able to see it when I opened the box. It really added to the proposal, and three years later, my wife still talks about how "I thought of everything."
As a side note, one of my dear friends got engaged a few months ago. He proposed at a park at night and he was saying how they had to pull out their iphones to see the ring. Not that there is anything wrong with that, but I would go with the lighted box.