A solid-state electronic electrochromic device (ECD) operates electronically rather than relying on the ionic motion that is common in electrochromic devices. The electronic ECD has at least one active layer sandwiched between two electrodes. The active layer is made of mixed metal oxides and may be made of a mixture of tungsten and praseodymium oxides. The electronic ECD may have only a single active layer, or may have multiple layers that have the same composition and that are separated by thin transparent metal films. Some versions of the electronic ECD incorporate a distribution of small metal particles within the active layer.