Metallic nanowire gratings have great potential to be used in display devices attributing to the unique surface plasmon resonant color shift by changing the refractive index of the ambient media. The modulator has the advantages of simple structure, high chromaticity and contrast, etc. Three pitches of bilayer metallic nanowire gratings with red, green and blue colors are respectively designed by simulation. In the experiment, the gratings with a pitch of 520 nm and an aluminum thickness of 50 nm are fabricated. The switching from bright green color state to dark state is achieved by changing the ambient medium from air to sucrose solution, and the contrast can reach 122. The feasibility of color display and adjustable brightness is verified theoretically and experimentally, which provides a new design scheme for the electro-wetting display devices in the future.