Multiple triangular orange light formations over central north seaI work on an offshore rig and was out on deck at night. I looked into the distance and saw an orange light, at first i dismissed it as a helicopter (although orange is an unusual light colour for them). The light vanished, so I thought it went behind a cloud. Seconds later, and much closer, a triangle formation of orange lights appeared, not moving, then in sequence 3 more evenly spaced triangles appeared before fading in the same order they appeared. I then shouted on someone to come and see, they never!! Then closer still, the same thing happened, this time with 5 formations, although this time I could see a faint light joining the formations together just under the bottom 2 lights, this went from the 1st set to the last set of lights in the formation. They then faded and I never saw anything else.