Abstract : Colors in animals are often produced chemically by pigments, but saturated colors can be physically generated by interference of light scattered by biophotonic nanostructures. Vivid structural colors including ultra-violet, violet, blue and green hues are abundant in birds and insects and frequently used in social and sexual communication, and crypsis. Over the past decade, I have pioneered the use of Synchrotron Small Angle X-ray Scattering (SAXS) as a high-throughput tool to structurally and optically characterize biophotonic nanostructures across hundreds of species of birds and arthropods, in a comparative evolutionary fashion. This large body of comparative structural knowledge has brought about the realization that despite their overwhelmingly diverse forms and functions, biophotonic nanostructures all develop intra-cellularly via processes that resemble colloidal self-assembly (phase separation, depletion-attraction) or templated via infolding membranes. However, the precise details of their intracellular development are unknown, considering these are non-model systems and because of the dearth of developmental studies. My interdisciplinary research creates novel interconnections among the fields of soft materials physics, photonics, evolutionary biology, and developmental biology, and happens to be highly relevant to current challenges in materials science and engineering of complex, structured mesophases and may biomimetically inspire novel ways of materials synthesis. In this talk, I will address the physics, evolution and biomimetic potential of organismal structural colors, before concluding with some exciting future directions in this unprecedented age of big data (–omics).