Why skies are blue instead of purple - Technology & science - Science - LiveScience | NBC News: ""Your eye can't tell the difference between that complex spectrum and one that is a mixture of pure blue and white," Smith said.
In other animals, the sky color is undoubtedly different. Outside of humans and some other primates, most animals have only two types of cones instead of three (dichromatic vs. trichromatic).
Honeybees and some birds see at ultraviolet wavelengths that are invisible to humans."
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