Full-color lanthanide (Ln) photoluminescent materials have attracted considerable interest owing to their potential applications in display systems and lighting technologies. Herein, full-color photoluminescent films have been designed and fabricated facilely with a fixed-component Ln-based (Ln=Tb and Eu) polymer hybrid doped with a proton-sensitive amide-type β-diketonated photosensitizer, N-(2-pyridinyl)benzoylacetamide (HPBA). The tunable photoluminescence emissions of the films are achieved by changing the amounts of OH(-) in the hybrid rather than varying the relative concentrations of the lanthanide ions and photosensitizers, thus representing a new paradigm for full-color displays. The emission color can also be finely tuned through the variation of the excitation wavelength, and white-light emission can be achieved when the given film is excited at the visible region (405 nm). The photophysical properties and the mechanisms of the intra- and intermolecular energy transfer before and after deprotonation have been investigated in detail. Meanwhile, the films might find application as vapoluminescent sensors due to their good stability, sensitivity, reversibility, and quick response when triggered by a base-acid vapor.