Do airplanes or helicopters ever fly at night using only white navigation lights? I've been trying to figure out if airplanes or helicopters ever fly at night with only white Nav Lights.

See this UAV video taken on July 12, 2015, 05:38 AM Pacific time in San Francisco, CA, USA.
There are no such things as white navigation lights - nav light, by definition, are red/green/white.

However, we're talking about filming lights at night. And the problem here is that the light source, no matter what colour, is a concentrated source of light in major contrast to the lack of light around it. And so the light will often 'burn in' on a camera and appear to be a lot of light, ie white, where the human eye will pick up the colours.