The universe bathes in a sea of light, from the blue-white flickering of young stars to the deep red glow of hydrogen clouds. Beyond the colors seen by human eyes, there are flashes of X-rays and gamma rays, powerful bursts of radio, and the faint, ever-present glow of the cosmic microwave background. The cosmos is filled with colors seen and unseen, ancient and new. But of all these, there was one color that appeared before all the others, the first color of the universe.
Source:
https://phys.org/news/2019-10-universe.html