Animals are living color. Wasps buzz with painted warnings. Birds shimmer their iridescent desires. Fish hide from predators with body colors that dapple like light across a rippling pond. And all ...

The swirling skies of Vincent Van Gogh's Starry Night illustrate a mystery that has eluded biologists for more than a century -- why do we perceive the color blue in the dimly lit night sky? A newly ...