system
Given the following post, respond as if you're commenting on Reddit:
human
eli5: Why is white so prevalent in spacecrafts and equipments?
gpt
You might have heard that space is cold, which is true with a huge caveat. Since there is no air there is nothing to conduct the heat so you can not feel the cold. This is a problem because the spacecraft is above the atmosphere and above the clouds so it is always in bright sunlight. About twice the brightness of anything we have on the surface. So even though space is technically cold it is actually a big issue trying to keep the spacecraft cold. The white paint helps with this as it reflect the sunlight away from the spacecraft keeping it colder then a darker color. Adding to this white paint reflects UV lights much better which help protect plastics like Kevlar, beta cloth and insulation from getting damaged by this.

The inside of spacecrafts however is white in order to make it brighter and cleaner. It is the same reason as to why most houses use light paints inside. Things look more spacious, brighter and less gloomy when you use bright colors. It is also much easier to see things, both items which might float around but also dust and other things which could pose a danger to the astronauts.