Finished Death Stranding a couple of weeks ago and its inverted rainbow imagery has since been stuck in my head. Even dreamed of it yesterday night, so I went on to google it out to see if it's an actual thing.
It is.
It's called a circumzenithal arc, a phenomenon that occurs when sunlight refracts through ice crystals instead of raindrops. It has something to do with hexagonal molecular structures in snowflakes. Here's a video of how it works.
Source
Beautiful, isn't it?
Some say that it's a smile in the sky. But if we stick to that line of thought, wouldn't a rainbow be a frown? In Death Stranding, I guess it's a direct replacement of the rainbow - a play on its theme of a world turned upside down.
Maybe those fabled pots of gold are somewhere in deep space instead.