Rectangular Red/Green Celestial Entity/UFO

I was walking back to my car at the campsite we were staying at for a festival called Lightning in a Bottle. It was about 3:30 a.m. after the last party ended and it was completely dark out with extremely clear skies. My friend and I stopped for a moment to look up and right when we looked up we saw the rectangular object, which appeared to be 2 dimensional or we were looking at maybe the bottom of some kind of craft or celestial phenomenon. It appeared in the shape of a rectangle but was divided in half to form two triangles (please see attachment). Please not the photo attached is a graphic design that I mocked up for reference but is not an actual photo. The object had very opaque tails of light and it was divided in two colors; red and green. The object lingered for a minute and then it began to ascend rapidly and eventually disappeared. I asked my friend I was walking with what he was seeing to cross reference that I wasn't losing it and he said he was seeing the same colors and shape of object in the sky. The festival had drones which we saw moments ago, but this was much larger, faster, and made no noise. It was also at least 10,000 feet off the ground.