According to a report published in the journal Science Advances, the blue color observed in blueberries, grapes, and certain varieties of plums is actually due to waxy layers present on the surface of the fruit. These waxy layers contain nanostructures that emit blue and ultraviolet light. Scanning electron microscopy has been used in research to observe these nanostructures. By mimicking the structure that creates the blue color in blueberries, methods could be developed to facilitate obtaining the blue color in plastic packaging materials and cosmetics.