system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: The color of water

Why is it, that if I pour myself a glass of water, it is see through, clear, etc... However, I can put that same water, into a plaster white bottomed pool, and the result is the pool looking blue... I thought maybe clouds?
gpt
When it's in the pool, the water is being hit by sunlight. Most of it is reflected back at you, but some of it is being absorbed. It turns out that water absorbs "red" wavelengths more readily (haha puns...) which leaves more of the wavelengths being reflected at the "blue" end of the spectrum. This is what you see.