[WinnyDaPoo]

In some WWII submarines, the sleeping room lined with bunks for the bulk of the staff, the lighting is red. Why? Because you can sleep in it easily -- it's always just red in that room because there are some day and night shifts even on a sub.

[simoncion]

The story that I heard (from my army dad) about red lights for night work was that red lights cause less night blindness than white lights.

Wikipedia corroborates this story, but indicates that a Navy study (from the 1980's) didn't find strong support for the practice.