Two lights, one amber, one green, taking turns passing each other, very fast, high up

My family and I lived in Wilton, California.  We lived on a fairly flat, rural, open, ranch area.  I was walking home from our friend's house across the street when the objects caught my eye.  They were two bright lights high up in the sky.  One was amber and the other was green.  They were moving very fast from the east to the west, from one horizon to the other.  From my vantage point they looked as though they were spheres many miles up and to the north.  They were taking turns passing each other in "leap-frog" formations.  The green light would stop and the amber light would zip past it.  Then the amber light would stop and the green light would zip past it.  They went from the East horizon to the West horizon in approximately 3-4 seconds.  I ran the remainder of the way home scared.  Out of breath, I immediately told my parents about my experience.   Due to my insistence they eventually believed me, called information and were given a phone number to call to report UFO sightings.  My Dad called the number (I don't remember the name of the organization that they called) and reported my sighting.  They informed my Dad that they had just received a call, reporting my same sighting, from one of forty firemen responding to a false alarm fire at Discovery Park, in Sacramento (due north from our location).  All had seen the same thing that I had.
Date is approximate.  PD