Many species of songbirds have evolved to have strikingly colorful plumage, aiding them in catching the eye of mates, signaling, and recognizing each other. These eye-catching patterns have long interested scientists, who previously assumed the birds' bright colors arose from only the visible feather layer. However, a new study, published in Science Advances, has shown that these colors are getting a boost in brightness from underlying feather layers, adding more complexity than previously assumed.