The existence of an anterior-posterior compartment boundary has been well documented in the wing of Drosophila melanogaster, and this boundary in Drosophila is known to play an important role in maintaining the Decapentapalegic signaling center at the middle of the wing. By analyzing the patterns of gynandromorph butterflies, we define the position of the compartment boundary in this group of insects. We then provide evidence that this boundary does define an early signaling center, but also reveal some interesting differences in the molecular nature of the boundary between Drosophila and butterflies. I will also discuss ongoing work to understand the developmental basis for transparency in butterflies, which is often used as a camouflage mechanism. Finally, green and blue coloration in butterflies is usually generated not by pigments, but rather by structural mechanisms, and I will discuss our progress in understanding how these nanostructures are created.