structural color

reflection

color

• pigment
• surface layers

fruit

• Brightest Thing in Nature: African Fruit Pollia Condensata – Biologists have discovered that the Pollia condensata fruit does not get its blue color from pigment but instead uses structural color – a method of reflecting light of particular wavelengths. Cell wall containing cellulose is laid down in layers, forming a chiral structure that is able to interact with light and provide selective reflection of only a specific color. As a result of this unique structure, it reflects predominately blue light. The thickness of the layers determines which wavelength of light is reflected. As a result, some cells have thinner layers and reflect blue; others have thicker layers and reflect green or red.
• butterflies<
• fish
• birds – peacock
• scarab beetle

That’s engineering

• wavelength – The distance between the peak and trough of one cycle of a wave of heat, light, or other energy.