Colloidal Photonic Crystals Toward Scalable Manufacturing and Reliable Functions

Colloidal photonic crystals (CPCs) have attracted considerable attention because of their specific optical properties and versatile structural functionality. While previous reviews have extensively covered the fundamental design and fabrication principles of functional CPCs, a systematic perspective on their transitioning from laboratory‐scale demonstrations to scalable manufacturing remains less explored. In this review, we therefore specifically fill this gap by summarizing recent advances on colloidal assembly, structural evolution, and stabilization strategies relevant to large‐scale fabrication and application‐oriented use. First, a concise overview of refining the classification of building blocks is provided for establishing a library to construct well‐defined periodic sophisticated photonic nanostructures. Second, we discuss scalable assembly from the perspective of processing constraints on how mild conditions, short assembly times, simplified procedures, and large‐area uniformity can be balanced. This is followed by discussing structural color modulation beyond stimulus‐based classification, and design strategies that enhance color fidelity, mechanical stability, and robustness. Emerging applications of these unique photonic systems, including anti‐counterfeiting, sensing, displays, and bio‐related devices, are highlighted. Finally, this review presents some challenges and perspectives on the development of colloid‐based scalable photonic materials, aiming to provide a scientific framework for bridging laboratory‐scale photonic materials with industrial‐scale manufacturing and reliable functions.