I wish I could run this picture in a larger size, because it is just gorgeous! Researcher Shu Yang at U. Penn (and her grad students) has developed a simple method to create surfaces that — like butterfly wings — contain both structural color (ie, the color we see depends on the way light interacts with the surface, rather than on colorants on the surface) and that repel water. There are lots of potential uses for such surfaces. Right now she has a grant to develop coatings for solar cells. Read more in my story: Optics & Photonics News – Creating Surfaces That Stay Bright and Dry.