If you haven’t already noticed, all the spacesuits that NASA astronaut use when conducting extravehicular activities (such as spacewalks) are white instead of any other color. The space agencies of China and Russia follow similar color schemes; but have you ever wondered why?
Those of us on Earth are shielded from the Sun’s harmful radiation by the Earth’s vibrant atmosphere, but those on the International Space Station aren’t. To help keep that radiation at bay, NASA went with white spacesuits. The color white reflects most of that space radiation away from the astronaut and back into space, protecting them from cancer and intense sunburn, among other things.
Astronauts sometimes wear other colors while in space, such as blue when onboard the International Space Station and orange when docking with or descending from the International Space Station, and that’s because they’re being shielded from space radiation by the spacecraft itself. Perhaps more importantly, the orange spacesuit makes astronauts more easily discernable to recovery crews when they arrive back on Earth.
NASA initially used silver-colored spacesuits when launching project Mercury, but none of those astronauts ever left the safety of their space vehicle. Later down the line, it was learned that white reflected space radiation better than silver, and so NASA adopted the white spacesuit color as a standard as astronauts began exploring the vacuum of space.