In this work, instantaneous tuning of emission color in a monolithic tellurite glass doped with Ho3+/Tm3+/Yb3+ ions by modulating excitation frequency is experimentally demonstrated for the first time. The green-to-red ratio of the emission is changed successfully by varying the frequency from 100 to 7500 Hz due to different population rates of transitions due to red and green emissions. Remarkable quantum yield values are obtained under irradiation at a low power density. A multicolor plus-shaped image is constructed for the glass using a galvanometer as a proof of concept for the potentiality of lanthanide-doped luminescent glasses as screen materials for volumetric displays. Additionally, the Judd-Ofelt analysis shows good radiative transition probabilities, and the calculated gain coefficient values indicate that favorable laser emission is also obtainable upon proper excitation. The obtained results are encouraging, revealing the potentials of lanthanide-doped glasses in a broad-band spectrum of photonic applications where tunable emission is demanded from a fixed monolithic material.