Bright white/green/red pulsating light pacing my flight over IranI was returning Florida from a business trip to Mumbai, India. I was on a Delta Airlines flight that left Mumbai and connected in CDG airport in Paris, France. I was in a busines class seat that had the option of watching the plane's location on a GPS map on the seat-back in front of me. It was dark and in the middle of the night; most everyone on the flight was sleeping at the time.I had a right window seat near the front of the plane. Since I have trouble sleeping on planes, I routinely looked at the GPS and then out the window. The route took us north through Iran, then turns left at Tehran and heads NW towards Europe. While still heading north through Iran (before Tehran), I noticed a light to the right of the plane, not too far away (less than 1 mile I'd guess), and slightly behind us. It was a white light, but soon it pulsed into a green light, then pulsed into a red light. It alternated between those 3 colors, but sometimes appearing yellow. It did not change colors in an pattern (white, red, green, red, white, green, yellow, green, white, and so on), nor were the times in a patern...sometimes it would go 10 seconds before turning colors, other times it would go 2-3 seconds.It was definitely pacing our plane, but would sometimes pull even with us nd other times fall back a bit. It was flying at the same altitude.Since Iran is hostile to the US, I began to get concerned that perhaps it was a military aircraft with malicious intent. I got the attention of a flight attendant and pointed it out to her. She too was surprised to see the other craft. She said she'd ask the Captain about it. At that point I'd seen it for perhaps 15 minutes, and then we began the left bank to head towards Europe - we were over Tehran. The light fell back and out of sight. As we straightened out and began an even flight again, I kept looking back. Sure enough, about 5 minutes later the light reappeared, catching up to a spot in about the 4 o'clock position. It continued to pulse and change colors. As the pre-dawn light started to lighten up I thought I could make out a shape...it looked like a rounded triangle - kind of like a football, cut in half, tip up. The lights apeared to be spinning with the craft, but very slowly.The flight attendant returned and said the Captain was too busy to discuss it at length, but he wasn't aware of any other aircraft flying with us and he couldn't see it when he looked (maybe we had just turned). I pointed it out to her again, and she gave a "hmmm", then added she was sure it was nothing to worry about.I continued to watch the thing for a combined hour....then suddenly it quite changing color and remained a bright white for perhaps a minute, then blacked out and I couldn't see it. As the sky totally lightened up over the next hour or so,I continued to watch for it but never saw it again.I've done that flight route over 15 times, both before and after that event, and have only seen the thing that one time.((NUFORC Note: Witness indicates that the date of the sighting is approximate. PD))