A major fabrication challenge is producing disordered photonic materials with angleindependent structural red color. Theoretical work has shown that such color can be produced by fabricating inverse photonic glasses with monodisperse, non-touching voids in a silica matrix. Here we demonstrate a route toward such materials and show that they have angleindependent red color. We first synthesize monodisperse hollow silica particles with precisely controlled shell thickness, then make glassy

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... al structures by mixing two types of hollow particles with the same core size and different shell thicknesses. We then infiltrate the interstices with index-matched polymers, producing disordered porous materials with uniform, non-touching air voids. This procedure allows us to control the light-scattering form factor and structure factor of these porous materials independently, which is not possible to do in photonic glasses consisting of packed solid particles. The structure factor can be controlled by the shell thickness, which sets the distance between pores, while the pore size determines the peak wavevector of the form factor, which can be set below the visible range to keep the main structural color pure. By using a binary mixture of 246-nm and 268-nm hollow silica particles with 180-nm cores in an index-matched polymer matrix, we achieve angle-independent red color that can be tuned by controlling the shell thickness. Importantly, the width of the reflection peak can be kept constant, even for larger inter-particle distances.