A tri wavelength diffracting modulation (TWDM) element, a TWDM imager, and methods of temporally and spatially modulating by using the same are disclosed. The TWDM element includes first and second sets of movable reflective rigid plates under independent electrical actuation, provides four different spatial configurations for reflecting and selectively diffracting incident radiation of three distinguished wavelengths. The TWDM imager is formed with a plurality of the TWDM elements in a regularly spaced planar array configuration on a planar substrate. Incident visible light is spatially modulated by the TWDM imager, either in a time sequential mode or via spatial combination with help of an aligned color filter array.