Spectacular triangle's seem in the sky

It was 1993 when this event happened. I was living in down town Sacramento, California. I don’t remember what time of year it was, but I lived on the corner of 13th street and F street. I always took my dog out for a potty walk, roughly between 10 and 11p.m. Across from our place was a vacant lot, that I always walked him in. I took him out that night as I always did and walked across the street to the vacant lot. It was a cool evening and the fog was hovering above the roof tops, when I noticed above me, in the fog, lights. I looked up and was amazed at what I saw.
There were three sets of triangular lights, each triangle was made up of three long strips of light, formed into each triangle. What ever it was, where ever they came from, was huge, I don’t even believe I could accurately describe the size. They were enter moving about each other, they were red and blue.
I could only compare what I was looking at, to some type of computer graphic design you might see on the web. I was so amazed that I ran back into the house and asked my then 15 year old son to come out and look too. He did, and we both stood there in the middle of the street amazed, at what we were watching above our heads, the lights moving in and out of each other, and changing about, while what ever was making them, hid in the fog.
I didn’t own a video camera at the time, or I would have tried to film the spectacular sight that was occurring. We stood there, my son and I, for a very long time. Two of our neighbors emerged from their apartment, and at first look, they laughed at us, like what the heck are they doing standing in the middle of the street. And then they too, glanced up to the sky above us, and muttered something to the matter of profanity when they too saw the lights. It was at that moment that the lights disappeared. I have never in my life before or since seem anything like it.
Witness indicates that date of incident is approximate.  PD