Achieving　high-quality　white　light　and　related　effective　modulation　is　crucial　for　the　development　of　solid-state　luminescent　materials.　However,　white　emission　is　frequently　manipulated　through　irreversible　chemical　routes,　departing　from　the　actual　applications　in　solid-state　lighting　devices　that　require　in-situ　modulation.　In　this　study,　we　designed　and　prepared　La3+/Dy3+/Eu3+　tri-doped　(K0.5Na0.5)NbO3　transparent-ferroelectric　ceramics,　which　exhibit　abundant　optical　properties　and　moderate　ferroelectricity.　For　the　characteristics　of　white　light,　the　emission　colors　could　be　regulated　by　adjusting　the　excitation　wavelength.　Meanwhile,　on　the　basis　of　the　decrease　in　photoluminescence　intensity　due　to　photochromic　(PC)　behavior,　modulations　of　white　emission　and　color　coordinates　were　realized.　The　regulation　of　optical　properties　through　the　physical　route　(i.e.,　maneuverable　light　illumination)　is　closer　to　practical　application.　In　addition,　the　excellent　fluorescence　temperature　sensing　properties　(a　maximum　relative　sensitivity　of　7.81　%　K-1　obtained　at　233　K)　and　high　PC　contrast　(75.8　%)　of　the　ceramics　provide　guidance　for　the　design　of　other　multifunctional　optoelectronic　materials　and　devices.