The Prettiest Sea Slugs Use Crystals in Their Skin as 'Pixels' of Color

Researchers found that many nudibranchs produce color using stacked guanine nanocrystals embedded in skin 'pixels'.

The team examined six species and used microscopy to identify nanocrystal arrays that generate structural color.

Random variation within each pixel's crystal layering reduces iridescence, making colors appear matte and bold.

The study was published in PNAS and suggests the mechanism could inspire sustainable color materials.