|We present a real-time algorithm for rendering of Morpho butterflies, using shading language. Morpho butterflies’ wings are brilliant blue, which is not a pigment color but a structural color. This distinctive blue color is a result of interference effect of light on scales of the wing. We regard the scales as bilayer structure for the sake of simplifying the model, while actually the scales consist of multiple layers. Weighted average of varying incident light in different angle is used in order to simplify the diffraction effect of light. Due to these simplifications, real-time rendering can be easily achieved without losing the unique features of the structural color of the wing, such as, the extraordinary uniform blue color with respect to the observation direction, and the change from blue to purple when the observation angle is large.