Vanadium dioxide (VO2) films were prepared on quartz glass and TiO2-coated quartz glass substrates by reactive RF-magnetron sputtering. The VO2 thin film with film thickness of 50 nm deposited on quartz glass substrates showed two kinds of regions with different color visible to the naked eye, i.e., the earth yellow region and the cyan region. Both XRD and Raman spectroscopy showed that the different color regions of the films had the different crystallinity quality and phase composition. Whereas, the VO2 thin films with film thickness of 50 nm fabricated on TiO2-coated quartz glass (with TiO2 film thickness of 50 nm) had uniform color and exhibited a larger change in transmittance at near infrared region than the VO2 thin films deposited on quartz glass did. A TiO2 buffer layer improved the crystallinity and uniformity of the VO2 film. Such very thin VO2 films with a TiO2 buffer layer have high potential for practical application in smart thermal glazing of windows.