A method and apparatus for rendering a color image on a delta-structured display are provided. The method for rendering a color image on a display apparatus in which a pixel expressing an input image is formed with delta-structured sub-pixels, the method comprising: (a) forming a scaling filter which is used to make the resolution of the input image correspond to the resolution of the display apparatus; (b) obtaining a representative value of a sub-pixel of the display apparatus corresponding to a consideration area which is an area processed by the scaling filter in the input image; (c) obtaining the value of the sub-pixel based on the difference of pixels in the consideration area in the input image; (d) performing gamma correction of the sub-pixel value so that the sub-pixel is appropriate to the display apparatus; and (e) rendering the gamma-adjusted sub-pixel value on the display apparatus. By using the sub-pixel rendering method of a display apparatus, resolution is improved and the color fringe that can occur due to sub-pixel rendering is reduced.