By UV–Vis spectroscopy, ESR study, X-ray photoelectron spectroscopy and theoretical calculation, a newly synthesized tetrazole-viologen based zinc(II) coordination compound, [ZnCl2(3-TzV)(H2O)] (3-TzV=N-(3-tetrazylbenzyl)-4,4′-bipyridinium), was found to exhibit electron-transfer photochromism. In addition to the commonly observed decrease in fluorescence intensity, the fluorescence color changes from green to blue during the coloration, and this change is reversible by altering UV–Vis irradiation and heating for at least seven cycles. The unprecedented photoswitching of fluorescence color for viologen-based photochromic compounds offers a good candidate for multicolor emitting display.