Abstract: The present invention provides an electrolyte for electrochromic devices, the substance comprising ?-butyrolactone (gamma-butyrolactone or GBL). The electrolyte may include polymethylmethacrylate. The electrolyte may further include a salt, such as a salt that includes lithium perchlorate or trifluorosulfonimide. In accordance with further aspects to the invention, the electrolyte may include propylene carbonate.

Abstract: The present invention provides apparatus and methods for multi-color electrochromic devices. In one embodiment, pixels of a first color electrochromic material (i.e. pigment) are arranged in first areas on a substrate with pixels of a second color electrochromic material in second areas to define a two-dimensional pattern of the first and second color on the substrate. When the applied electric field or current supplied to each pixel is changed, the device may produce the respective colors of the electrochromic materials and may produce a blended color because of the arrangement of the pixels. In accordance with further aspects of the invention, the electrochromic materials may form a design, pattern, logo, or picture when the electrochromic materials are activated. In yet further aspects of the invention, a substrate is masked and unmasked as a plurality of colors are applied to the substrate to produce a multi-color electrochromic display.