Structural color facts for kids

The brilliant iridescent colours of the male Peacock's tail feathers are created by structural coloration, as first noted by Isaac Newton and Robert Hooke.

Structural coloration is a coloring that results from the special structure of the surface. Sometimes structural coloration is combined with pigments: for example, peacock tail feathers are pigmented brown, but their structure makes them appear blue, turquoise, and green, and often they appear iridescent.

English scientists Robert Hooke and Isaac Newton were the first who observed structural coloration. Thomas Young described its principle a century later and called it wave interference. Young described iridescence as the result of interference between reflections from several surfaces of thin films, combined with refraction as light enters and leaves such films. The geometry then determines that at certain angles, the light reflected from both surfaces adds (interferes constructively), while at other angles, the light subtracts. As a result, different colors appear at different angles.

Images for kids

• 

  Robert Hooke's 1665 Micrographia contains the first observations of structural colours.

• 

  In 1892, Frank Evers Beddard noted that Chrysospalax golden moles' thick fur was structurally coloured.

• 

  Electron micrograph of a fractured surface of nacre showing multiple thin layers

• 

  Magnificent non-iridescent colours of blue-and-yellow macaw created by random nanochannels

• 

  The most intense blue known in nature: Pollia condensata berries

• 

  Variable ring patterns on mantles of Hapalochlaena lunulata

• 

  One of Gabriel Lippmann's colour photographs, "Le Cervin", 1899, made using a monochrome photographic process (a single emulsion). The colours are structural, created by interference with light reflected from the back of the glass plate.

• 

  European bee-eaters owe their brilliant colours partly to diffraction grating microstructures in their feathers

• 

  The male Parotia lawesii bird of paradise signals to the female with his breast feathers that switch from blue to yellow.

• 

  Brilliant green of emerald swallowtail, Papilio palinurus, is created by arrays of microscopic bowls that reflect yellow directly and blue from the sides.

• 

  Iridescent scales of Lamprocyphus augustus weevil contain diamond-based crystal lattices oriented in all directions to give almost uniform green.

• 

  Hollow nanofibre bristles of Aphrodita aculeata (a species of sea mouse) reflect light in yellows, reds and greens to warn off predators.

• 

  Thin-film interference in a soap bubble. Colour varies with film thickness.

See also

In Spanish: Coloración estructural para niños