Some beautiful colors are created in nature by means of pigment, but others, especially shades of blue, have a clever way of reflecting light. Researchers have now delved into this trick using blueberries.
If you see a bird with bright red wings, the pigment particles in that feather absorb all colors of light except red. But if you see a butterfly or peacock with surfaces of a beautiful bright deep blue, there is a skeletal color. This is created because light is selectively reflected off a dye-free surface with a special structure.
When a researcher in Colorado saw a blueberry in a bush with a similarly brilliant metallic blue glow, she wanted to know: How exactly does the berry do? Because this shade is rare in plants. I found that berries use layered lipid molecules to adequately reflect light. It is known that only one manufacturer does this, but there is no connection between them.
Then you might think, if this was done separately by two plants, there must be an evolutionary advantage to this trick. One theory now is that the lipid layer also has an important protective effect. Another is that the color is so beautiful that birds often use the berries as decoration in mating rituals and the plants have ended up in many gardens for the same reason.