system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5 Why is there so few natural blue colored foods?
gpt
Plants have only three pigments: Anthocyanin (red), xanthin (yellow), and chlorophyll (green). It's pretty difficult to combine them in a way that yields blue. Some plants get close, but it's really more of a purple color than a true blue.