Yes, very few naturally-occurring foodstuffs are blue.
But Also: Historically, beyond some narrow contexts (blueberries, blue cheese, ...), "blue food" would almost always be a red flag for spoiled/contaminated & probably dangerous food. So natural selection would favor "Avoid Blue Foods" instincts.
Anecdote: Back in the early '60's, my youngest sister asked mom to make her a blue(berry) birthday cake. Mom was an excellent baker...but my sister's visceral reaction to the color prevented her from eating any of the cake.
But Also: Historically, beyond some narrow contexts (blueberries, blue cheese, ...), "blue food" would almost always be a red flag for spoiled/contaminated & probably dangerous food. So natural selection would favor "Avoid Blue Foods" instincts.
Anecdote: Back in the early '60's, my youngest sister asked mom to make her a blue(berry) birthday cake. Mom was an excellent baker...but my sister's visceral reaction to the color prevented her from eating any of the cake.