system
Given the following post, respond as if you're commenting on Reddit:
human
How does sun bleaching work?

I get the science of how we see color via reflected light but I'm genuinely curious about how if an object is left in the sun for an extended period of time it will seemingly lose its color. How does it happen and what causes it?
gpt
The UV in the sun is pretty damaging and will chemically decompose many compounds (like dyes - whether artificial or natural) If you leave plastic out in the sun, the UV will usually make it brittle and yellowed fairly quickly unless the plastic is designed for outdoor use.