The study presents a supramolecular assembly approach to create highly emissive blue and green halide perovskites with near-unity photoluminescence quantum yield (PLQY). The method involves using crown ether-assisted assembly to pack [Hf/ZrBr6]2- emitting units into tunable symmetries, resulting in (18C6@K)2HfBr6 powders with a blue emission PLQY of 96.2% and (18C6@K)2ZrCl4Br2 powders with a green emission PLQY of 82.7%. These materials exhibit strong electron-phonon coupling and microsecond PL lifetimes, making them suitable for various optoelectronic applications. The powders maintain high PLQY in solution-processable semiconductor inks and can be used in thin-film displays and 3D printed architectures, demonstrating high spatial resolution. The supramolecular assembly approach also allows for the tuning of emission colors and PLQY through alloying at the halide site, further expanding the potential applications of these materials.The study presents a supramolecular assembly approach to create highly emissive blue and green halide perovskites with near-unity photoluminescence quantum yield (PLQY). The method involves using crown ether-assisted assembly to pack [Hf/ZrBr6]2- emitting units into tunable symmetries, resulting in (18C6@K)2HfBr6 powders with a blue emission PLQY of 96.2% and (18C6@K)2ZrCl4Br2 powders with a green emission PLQY of 82.7%. These materials exhibit strong electron-phonon coupling and microsecond PL lifetimes, making them suitable for various optoelectronic applications. The powders maintain high PLQY in solution-processable semiconductor inks and can be used in thin-film displays and 3D printed architectures, demonstrating high spatial resolution. The supramolecular assembly approach also allows for the tuning of emission colors and PLQY through alloying at the halide site, further expanding the potential applications of these materials.