Subwavelength gratings attract a high level of interest in wavelength selection for optical filter. High reflection and efficient wavelength selection are attained using the resonant effects of the gratings. Some subwavelength effects of gratings such as antireflection and structural color are studied. Combining with the MEMS actuator, the pitch of the gratings can be varied, and thus the color of the grating is modulated. Moreover, we also fabricated subwavelength reflection-variable gratings from silicon wafer and the optical characteristics have been investigated.