In this study, color-tunable nanocrystalline phosphors of ZnS: ( ratio = 1, 0.85, 0.75, 0.65, 0.5) were synthesized at a low temperature using the solid-state reaction method. The emission spectra of ZnS: samples excited at exhibited two emission peaks. The blue-light emission is due to the donor-acceptor recombination in the ZnS host, and the orange-light emission is attributed to the transition of ions. The chromaticity coordinates of the phosphors changed from orange, near white, to blue with decreasing ratio. The local strain and the quantum efficiency of the phosphors are also investigated.