Fully visible flying saucer

Myself and my two cousins were out in front of our Grandmothers playing with remote controlled cars.  We for some reason looked up to the night sky to see a disc shaped craft approximately 100 to 200 feet in length and  maybe 50 feet in height.  The craft was very low in the sky maybe fifty feet taller then your average telephone pole and It had several different colored lights circling the craft and several black "windows" around the saucer.  The craft was a light grayish blue color that to this day I have never seen on any aircraft.  It passed over our grandmothers house making no sound at all.  We witnessed it in the front for about one minute moving very, very slowly as if it was studying us.  We then ran through the house to the back yard and the saucer was gone.  I spent four years in the United States Marine Corps working in and around aircraft from several branches of the military.  I have never seen an aircraft that matches the color or metal con! struction to this aircraft.  The saucer appeared to be one smoothly constructed craft something that I have never seen since.  I have seen other things in the sky since then and have heard numerous stories from around this area, even a couple of abduction stories, and was wondering what information if any you guys had on this area.
Witness indicates that date is approximate.  PD