Infra red to ultra violet five rainbow colored lights in a straight line strobing in sequence left to right.then moving off quickly.I was driving home from a job in a town away from my home town. I had just turned west on I-70 at Crecent Junction, Utah and had traveled just a few miles past the town of Thomson Utah when I glanced over to my left and saw way off on the horizon a straight line formation of five different colored flashing lights. I was with my partner and I exclaimed that I thought that there were five helecopters hovering out there with different colored strobe lights attached to them. As he continued to stare at them he told me to pull over because something was strange. He noticed that the lights were flashing in sequence from left to right and were very stationary in the sky. I said that they must be radio towers and he said that radio towers have lights all the way up the tower not just one light at the top. Then we noticed that the lights weren't really the type of light that we were accustomed to seeing. They had a funny little glow that didn't quite look normal. Then we realized that they were in the same color sequence as a rainbow, from infra red to ultra violet and in five different colors.I decided to turn on my amber yellow strobe for some unknown reason and when I did that the flashing sequence started to speed up. They started flashing in sequence from left to right very fast and they started to grow together very quickly which means this thing started to speed off in the opposite directing very vast. It's really hard to judge distance or size the way they sat out on the dark horizon but I would guess the formation to be about two hundred feet between the unfra red light and the ultra violet light, but I really don't know for sure. There was no sound that we could hear. We couldn't see any other shape attached to the lights. We saw only the five lights. My partner looked over at me after it disappeared an asked me "How long do you think we sat and watched those lights?" I replied, "About five minutes." I retired right after that so I haven't seen him since then but I'm sure I can find him and he will have no problem cooberating my story.This is the second report that I'm sending and I've now reported all of the ufos that I've seen in my lifetime.