Bright white low-flying "light" fades to green and then fades out.I was driving home (towards Lompoc, California) on highway #1 (approximately 5 miles out from Gaviota/coast, when in the night sky ahead of me I saw what at first struck me to be a moderately bright white star; however, as I watched this "star" it was plainly apparent that: (1) It was at what I would call "airplane runway approach height" in the sky (perhaps 2 miles altitude. (2) It was obviously MOVING at a slow but deliberate pace (again, I could best compare the speed to that seen with airplanes on their landing approach. Next, I pulled my car over to the shoulder of the highway for a better look (as it seemed unusual to see aircraft in this vacinity (as it is very close to Vandenberg AFB and their no-fly zone). There were only a few cars on the highway and this was a very clear night (no fog or clouds). -Star visibility was good. I watched the craft/light move southwest (towards the coast) when it appeared that the light did a gradual fade to light green...then solid/deep green (as if someone were controlling it with a dimmer switch to control its intensity of color and brightness). I continued to watch the light for about a minute more and again, it faded; but this time it gradually dimmed completely out and I could not locate it within the clear night sky. I am familiar with satellites, but must stress to you that this light was very low in the night sky (at low-flying airplane altitude. I also am familiar with iridium satellites and their tell-tale green flashes. This light did not flash at all and was much brighter than any satellite I have seen. Even though the craft was low in the sky, I could not make out a shape.((NUFORC Note: This witness is well known to NUFORC, and we consider her to be exceptionally reliable. We have spoken with her about the sighting, and we have no explanation for what it was she witnessed. The object was moving to the southwest, which rules out most satellites. Also, as she watched the object fly from her right to left, she witnessed a green light, which rules out any kind of conventional aircraft. PD))