Perhaps more intriguing than the static color mechanisms found in nature are the numerous examples of organisms that can change color dynamically. Many organisms change color with season, in response to their environment, or for communication. ese biological photonic systems are responsive to stimuli, either internal stimuli such as the release of hormones or neurotransmitters, or external stimuli such as humidity or environmental toxins. e ability, in some form, is surprisingly widespread; examples abound in land and marine animals and plants. Among these active biological photonic systems are a select few examples that are even more fascinating than the others from an applications perspective. eir ability to control color change is so profound, and the structures that do so are sufficiently complex that we are yet unable to replicate the structures or their complete performance. Within these organisms are photonic systems that offer potential inspiration for a wide range of new applications, and specific advantages over existing technologies. Many of these applications are similar to those we have already discussed for the static structures, such as sensors, components for optical circuits, fashion, and security. One of the biggest areas of potential impact and interest is in displays, particularly in less conventional technologies such as flexible displays. Bioinspired dynamic photonic structures may enable completely new paradigms such as biodegradable and biocompatible displays.