In Nordic mythology there’s the Bifrost that connects Midgard to Asgard which is a rainbow bridge comprised of 3 colors.
In Chinese mythology, Nuwa (or Nüwa) is celebrated for her act of repairing the heavens after a great catastrophe. A celestial battle between the gods resulted in the collapse of the sky and a fragmented earth. Nuwa, the mother goddess and creator of humanity, took it upon herself to restore order. She took 5 colors which are symbolic of the elements and repaired it.