<p>Persistent luminescence materials are promising for night-vision displays, background-free medical diagnostics, and high-resolution radiography, yet achieving efficient violet, yellow, and red emission within a single robust and scalable host remains a longstanding challenging. Here, we overcame this limitation by constructing Gd³⁺-mediated cluster traps within alkaline-earth fluorochlorides to minimize energy loss during electron migration. These clusters serve as both intrinsic emitters and efficient energy transfer platforms for various activators, including Eu²⁺, Sm²⁺, Tb³⁺, and Mn²⁺, enabling bright and spectrally tunable multicolor persistent luminescence upon X-ray irradiation. The persistent luminescence intensity of Eu²⁺ is enhanced by up to 32.7-fold upon Gd³⁺ codoping. Moreover, violet persistent luminescence from Eu²⁺ is employed to excite perovskite quantum dots for full-color time-domain dynamic displays, while Sm²⁺ emission facilitates low-dose, high-resolution delayed X-ray imaging. These findings establish a generalizable strategy for designing efficient multicolor persistent materials for advanced multifunctional optical technologies.</p>