What is the Color of the Universe?

January 20, 2023

Group standing in front of the Milky Way to depict the color of the universe

In 2002, astronomers at Johns Hopkins University conducted a study to determine the color of the universe from the light we see. They averaged the light emitted from a large sample of 200,000 galaxies from the Australian 2dF Galaxy Redshift Survey. The galaxies emitted colors throughout the entire electromagnetic spectrum, but they found the one color that averaged out to be a composite color of all the light in the universe.

They found that the color of the universe overall is a shade of beige. More specifically, the color corresponds to the computer HEX code (hexadecimal color used for web design) #FFF8E7 or the RGB color code (red, green, and blue, used on computer monitors, TV screens, and mobile devices) of red 255, green 248, and blue 231. 

The astronomers at Johns Hopkins voted on what they would call the color, and even though “cappuccino cosmico” received the most votes, they decided on another suggestion. They named the color “cosmic latte.”

The color of the universe, cosmic latte
The Color of the Universe, Cosmic Latte

The universe appears to have more areas that produce red and green light over blue light, but over the past 10 billion years, the color of the universe has become less blue, indicating that the redder stars are now more prevalent. If, however, the blackness of space is introduced and averaged over the entire sky, the color appears almost, but not quite, entirely black.

But “cosmic latte” wasn’t the first color the astronomers had come up with. They initially reported the color of the universe as turquoise but admitted that their original findings hadn’t considered the science of color enough.

The researchers took the cosmic spectrum, which was a graph, and assigned each wavelength a color. They then replaced each wavelength with the color the human eye sees and varied the intensity in proportion to the intensity of the wavelength in the universe. What they found after their calculations was that the human eye would see a pale turquoise.

But a scientist at the Munsell Color Science Laboratory at the Rochester Institute of Technology helped the astronomers discover that a program they had used to calculate the color had set a feature called a “white point” or a point at which light appears white depending on the environment the light is viewed in. Different lights make the white point a different color depending on the environment, such as how tungsten lights make the white point a little more yellow to the human eye.

When the astronomers adjusted the white point, they calculated that the observer looking at the light of the universe in a dark environment would actually see a beige color. If they were in daylight, the color would be a faint red, and indoors the color would be blue. 

But that isn’t quite the end to the question because researchers still need to more accurately measure the wavelengths of color of the universe, and they still need human observers to see the light to get a final, succinct opinion.

Sources: NASA, Science Focus, Headlines @ Hopkins

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Daniel Ganninger - The writer, editor, and chief lackey of Knowledge Stew, the author of the Knowledge Stew line of trivia books, and editor of Fact World and the Knowledge Stew sister site on Medium, our ad-free subscription sites (you can find out how to join below). I hope you find things here to annoy those around you with your new found knowledge.

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