Scientists at Ben-Gurion University of the Negev in southern Israel have cracked the code of how damselflies produce their striking colors, in a discovery that could help accelerate the replacement of toxic synthetic pigments across industries ranging from cosmetics to textiles.

Damselflies, often colored in metallic turquoise, blue, green, or red, resemble miniature helicopters that whizz over bodies of water during the warmer months.

Their colors are achieved through photonic glasses — tiny spheres packed together randomly to scatter light.

To counter the washed-out effect that can result from slight variations in sphere size, the damselfly has evolved two corrective mechanisms, according to an article published at the end of last month in the Proceedings of the National Academy of Sciences (PNAS).

In the first, the density of the spheres drops as they get larger, ensuring that each sphere reflects the exact same shade of color.

In the second, the spheres are loaded with a yellow pigment. This acts like a filter, absorbing unwanted light while making the........

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