The striking luminescence of the Morpho family combines with the rich hues of Lycaenidae butterflies to form a universally pleasing palette of color. Many morpho butterflies are colored in metallic, shimmering shades of blues and greens. These colors are not a result of pigmentation, but are an example of iridescence through structural coloration. Specifically, the microscopic scales covering the morpho’s wings reflect incidental light repeatedly at successive layers, leading to interference effects that depend on both wavelength and angle of incidence/observance. Thus, the colors appear to vary with viewing angle, but they are actually surprisingly uniform, perhaps due to the tetrahedral (diamond-like) structural arrangement of the scales or diffraction from overlying cell layers. The wide-angle blue reflection property can be explained by exploring the nanostructures in the scales of the morpho butterfly wings. These optically active structures integrate three design principles leading to the wide-angle reflection: alternative lamellae layers, Christmas tree-like shape, and zigzag pattern of the ridges.