Circular UFO with lights around outer edge in night sky

It was early summer around 1980.  I would have been about 12 years old at the time.  It was not long after dark.  Weather was warm with clear skies.  I was in the family room of my parent's house, looking out a large picture window.  Windows on both sides of the picture window were open to let in an evening breeze.  
Directly in front of me above the trees across the street, a large circular UFO flew directly towards my parent's house.  The craft was darker than the night sky and could be seen as a circle.  The outer circumference of the craft had multi-colored lights all the way around.  Either the craft was rotating as it moved forward or the lights were changing color in a way that mimicked rotation.  The craft moved somewhat slower than I would have expected for low-flying light aircraft.  The craft's altitude appeared to be below 500 feet.  I estimate the craft was 60 to 100 feet across.  I never heard the craft make a sound.  As it passed above my parent's house, I ran to the front door and out into the front yard.  I again briefly saw the craft as it went over the treeline behind my parent's house.  The light pattern on the craft was very similar to another UFO report I found here, except the lights I saw formed a complete circle around the outer edge of the craft: 
http://www.ufocasebook.com/i84encounter.html.
Witness indicates that the date of the event is approximate.  PD