Structural colour arises from light interacting with nanoscale architectures, yet generalizable design rules for engineering such effects remain limited. Here, we introduce a predictive design framework for tunable structural colour based on simplified Morpho‐inspired photonic nanostructures. Using electromagnetic finite‐element simulations, we systematically vary geometric parameters and derive a linear scaling law linking structural dimensions to reflection wavelength, enabling both forward colour prediction and inverse geometry estimation. Angle‐resolved analyses reveal that reflectance is maximized at shallow incidence angles, offering insights for wide‐angle optical functionality. To support practical design workflows, simulated spectra are mapped into RGB colour space for intuitive visualization. This framework provides an efficient route to engineer bioinspired photonic surfaces with tunable colour responses, relevant for coatings, sensors, and optical materials.
Rosnitschek et al. (Thu,) studied this question.