Tellurite glasses have been widely studied due to their capability to incorporate high concentrations of rare earth ions and obtain coloured light emission, however, high efficiency has not been achieved. In this manuscript, luminescence properties and up-conversion emission in tellurite-zinc glasses doped with Er 3+ −Yb 3+ −Tm 3+ , based on the colour mixing of red, green and blue light, is reported. The samples were characterized by UV-visible to infrared absorption spectroscopy and up-conversion spectra. Tuneable up-conversion emission was obtained by modifying the concentration of the rare earth ions and adjusting the laser excitation power at 972 nm. The addition of Yb 3+ ions improve the efficiency of the up-conversion process, because acts as a donor via energy transfer to Er 3+ and to Tm 3+ . These materials are propitious candidates for applications in the development of photonic devices and solid-state lighting.