A color image sensor includes a plurality of pixel cells arranged in a pixel array. A plurality of color filters is arranged in a color filter array disposed over the pixel array. Each color filter is aligned with a corresponding underlying pixel cell. An optical isolation grid is disposed over the color filter array such that incident light is directed through the optical isolation grid prior to be being directed through the color filter array to the pixel array. The optical isolation grid includes a plurality of sidewalls arranged to define a plurality of openings in the optical isolation grid. Each opening is aligned with a corresponding color filter such that each color filter is optically isolated by the optical isolation grid to receive incident light only through a corresponding aligned one of the plurality of openings.