system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5 how denim became so widespread and why blue became the color of choice?
gpt
Denim is so popular because it's a relatively durable material that's still pretty comfortable to wear and yet is cheap to boot, so it's pretty much the perfect material for the physical laborers that were the majority of people until very recently. Blue on the other hand is because blue dye was the cheapest, blue also doesn't show stains compared to many other colors.