Abstract: An electrochromic device and method, the device including: a first transparent conductor layer; a working electrode disposed on the first transparent conductor layer and including nanostructures; a counter electrode; a solid state electrolyte layer disposed between the counter electrode and the working electrode; and a second transparent conductor layer disposed on the counter electrode. The nanostructures may include transition metal oxide nanoparticles and/or nanocrystals configured to tune the color of the device by selectively modulating the transmittance of near-infrared (NIR) and visible radiation as a function of an applied voltage to the device.