Disclosed is a method for alleviating color shift of a display panel at a large viewing angle. The panel includes a sub-pixel array formed by R, G, B sub-pixels, and black matrix areas located between the sub-pixels. The method includes providing, above the sub-pixel array, an optical grating that is parallel with the sub-pixel array. The optical grating includes transparent areas and non-transparent areas. The non-transparent areas are provided above the black matrix areas. The optical grating is configured as such that when a sub-pixel is observed at a large viewing angle, light transmitted through the sub-pixel is partially blocked by the non-transparent areas of the optical grating.