•Optical thermometry applications of the Tm3+/Er3+/Sm3+ tri-doped TeO2-Li2O-ZnO (TLZ) glasses has been investigated.•The highest value of relative thermal sensitivity was 2.47 %K−1, with the FIR between the 530 nm and 458 nm emissions.•White-light emission was achieved by adjusting the doping concentration of Sm3+ ion.•The color coordinates CIE changed from white, (0.308, 0.317) at 299 K, to yellow, (0.416, 0.514) at 455 K. Display omitted The potential of Tm3+/Er3+/Sm3+ tri-doped TeO2-Li2O-ZnO (TLZ) glasses for temperature sensors using color emissions and for generating white light sources was investigated. The samples were successfully synthesized by melting quenching technique in air atmosphere. We have used fixed concentrations of Tm3+ (0.2 mol%) and Er3+ (0.5 mol%) ions, and three Sm3+ concentrations: 0.2, 0.5, and 1.0 mol%. Particularly, we have analyzed the fluorescence intensity ratio (FIR) corresponding to the emissions of these ions as a function of the temperature. As a result, the highest value obtained to the relative thermal sensitivity was 2.47%K−1 for the FIR related to the emissions at 530 nm and 458 nm of the sample doped with 0.5 mol% of Sm3+. In addition, white-light emission was achieved by adjusting the doping concentration of Sm3+ ions. Moreover, we obtained a CIE color coordinates changing from white, (0.308, 0.317) at 299 K, to yellow, (0.416, 0.514) at 455 K. These results showed that these TLZ glasses are promising platforms for optical temperature sensing, for example, such as safety signal in high-temperature environment.