Smart shape memory polymers (SMPs) can memorize and recover their permanent shape in response to an external stimulus, such as heat, light, and solvent. They have been extensively exploited for a wide spectrum of applications ranging from biomedical devices (e.g., surgical stents and sutures) and implants for minimally invasive surgery to aerospace morphing structures and self-healing materials. However, most of the existing SMPs are thermoresponsive and their performance is hindered by slow response speed, heat-demanding programming and recovery steps. Although pressure is an easily adjustable process variable like temperature, pressure-responsive SMPs are largely unexplored. Here, by integrating scientific principles drawn from two disparate fields that do not typically intersect - the fast-growing photonic crystal and SMP technologies, we report a new type of SMP that enables unusual "cold" programming and instantaneous shape recovery triggered by applying a contact pressure at ambient conditions. These stimuli-responsive materials differ greatly from existing SMPs as they enable orders of magnitude faster response, striking chromogenic effects, and room-temperature operations for the entire shape memory cycle, promising for applications ranging from chromogenic pressure and chemical sensors to novel biometric and anti-counterfeiting materials. Moreover, this interdisciplinary integration enables fabrication of reconfigurable photonic crystals and simultaneously provides a simple and sensitive optical technique for investigating the intriguing shape memory effects at nanoscale.