For the French Fauvist painter and color gourmand Raoul Dufy, blue was the only color with enough strength of character to remain blue “in all its tones.” Darkened red looks brown and whitened red turns pink, Dufy said, while yellow blackens with shading and fades away in the light. But blue can be brightened or dimmed, the artist said, and “it will always stay blue.”

Scientists, too, have lately been bullish on blue, captivated by its optical purity, complexity and metaphorical fluency. They’re exploring the physics and chemistry of blueness in nature, the evolution of blue ornaments and blue come-ons, and the sheer brazenness of being blue when most earthly life forms opt for earthy raiments of beige, ruddy or taupe.

One research team recently reported the structural analysis of a small, dazzlingly blue fruit from the African Pollia condensata plant that may well be the brightest terrestrial object in nature. Another group working in the central Congo basin announced the discovery of a new species of monkey, a rare event in mammalogy. Rarer still is the noteworthiest trait of the monkey, called the lesula: a patch of brilliant blue skin on the male’s buttocks and scrotal area that stands out from the surrounding fur like neon underpants.

Still other researchers are tracing the history of blue pigments in human culture, and the role those pigments have played in shaping our notions of virtue, authority, divinity and social class. “Blue pigments played an outstanding role in human development,” said Heinz Berke, an emeritus professor of chemistry at the University of Zurich. For some cultures, he said, they were as valuable as gold.