The luminescent properties of Ca₂Nb₂O₇ matrix and Ca₂Nb₂O₇: Pr³⁺ were studied in this work. In addition to the emission band from NbO₆ octahedra, the orange-red emission aroused by oxygen interstitial defects was observed in Ca₂Nb₂O₇. When Pr³⁺ was introduced, both of the matrix emission and the characteristic Pr³⁺ luminescence could appear simultaneously under suitable excitation wavelength. By further adjusting the doping concentration, color manipulation from blue-green to pink and red could be realized in Ca₂Nb₂O₇: Pr³⁺. In particular, a warm white light could be achieved when doping 0.1% Pr³⁺. Based on the luminescent results, the underlying mechanisms were discussed and proposed. The color manipulation results suggest that Ca₂Nb₂O₇: Pr³⁺ is promising for various fields related to lighting, displaying, and imaging.