cdeslandes

A yellowish green (greenish yellow?) is the color the eye is most sensitive to.
Those of us old enough to remember monochrome computer monitors will tell you that green was less tiresome than amber, because you didn't need to use so much light intensity.

A white car may be more visible at night, but is doesn't matter as much as the lights.
During the day, a dirty white car will actually be less visible, blending in its environment.

As for red, the thing in Japan is purely a cultural thing. You don't see many peple wearing red either.