Variable transmission covering systems that can be used, for example, to control the amount of light passing through a window in a building. Using transmissive electrophoretic media that can switch between a first and second optical state, the invention can be used to change the color and/or transmissivity of a structure (or structures) that is placed in front of an object. In some embodiments, the variable transmission system can change transmission and color on command.

Window controllers and methods for controlling tinting and other functions of tinting zones of multi-zone tintable windows and multiple tinting zones of a group of tintable windows.

Window controllers and methods for controlling tinting and other functions of tinting zones of multi-zone tintable windows and multiple tinting zones of a group of tintable windows.