Never-before-seen method for making the color blue found in stingray spots

[Still Waters]

Bluespotted ribbontail rays create blue in a unique way, researchers report in a new study. Novel nanostructures give the stingrays their eponymous spots, the study shows, intricately contorting light on the rays' skin to form a vivid blue that doesn't change with viewing angle.

Blue is a tricky color for living things to conjure. Most shades in the natural world are produced by compounds that evolved to absorb sunlight and emit a particular color. In cases where red light is emitted, the chemical needs to absorb the more energetic wavelengths, of greens, blues, and violets.

https://www.sciencealert.com/never-before-seen-method-for-making-the-color-blue-found-in-stingray-spots

The study was published in Advanced Optical Materials.