Ce3+, Eu3+, and Tb3+ singly doped, Ce3+-Tb3+, Tb3+-Eu3+, and Ce3+-Eu3+ doubly doped, as well as Ce3+-Tb3+-Eu3+ triply doped LiYSiO4 phosphors were prepared by a high-temperature solid-state reaction technique. Rietveld refinement was performed to determine the structure of host compound. The cross-relaxation (CR) of Tb3+ is quantitatively analyzed with the Inokuti-Hirayama model of energy transfer (ET), and the site occupancy is confirmed by emission spectra of Eu3+. ET and metal-metal charge transfer (MMCT) are systematically investigated in Ce3+-Tb3+, Tb3+-Eu3+, and Ce3+-Eu3+ doubly doped systems. The combined effects of ET and MMCT on luminescence and emission color of Ce3+-Tb3+-Eu3+ triply doped samples are discussed in detail, showing that the photoluminescence emission is tunable in a large color gamut.