A method of designing guided-mode resonance filter (GMRF) for three-primary-color is proposed under oblique incidence. The effects of incident angle on the guided- mode resonance filter reflection spectrum are investigated with the method of rigorous coupled wave analysis (RCWA). A single resonance splits into two formants under oblique incidence by TM-polarized light. By adjusting incident angle, one resonance wavelength is located in visible wavelength range, and the other one falls inside the infrared spectrum and the wavelength of the visible light can be tuned by incident angle. A 544 nm grating period guided- mode resonance filter is designed and fabricated for three-primary-color by adjusting and optimizing the parameters of the device . The fabricated filter exhibits blue, green and red color responsed at incident angles of 26.8°、39.6°、46.0° and it has a bandwidth of 5 nm with efficiency near 80%. Besides, when it works as blue and green color filter, it has a larger period compared with traditional sub-wavelength structure and greatly reduces the cost of grating fabrication. The experimental result promotes the application of guided-mode resonance structure in color filters and it has active guidance meaning for the fabrication of large-period guided-mode resonance device.