An image sensor and a method for fabricating the same are disclosed, in which a partial light-shielding layer is additionally arranged on a path of a particular colored light, for example, a red colored light that may cause excessive permeation, to partially shield the corresponding red colored light in a state that red colored light, green colored light and blue colored light are permeated into each photodiode of a semiconductor substrate, so that the permeation position of the red colored light coincides with that of the green colored light and the blue colored light each having the wavelength shorter than that of the red colored light, thereby normally generating optical charges caused by the red colored light in an effective depletion area of the photodiode like those caused by the green colored light and the blue colored light. The permeation position of a red colored light, a green colored light and a blue colored light coincides with one another within a depletion area of a semiconductor substrate to obtain an optimal effective ratio from respective optical charges and the uniform quantity of the respective optical charges can be transferred/discharged to an interpolation circuit by signal processing transistors, thereby effectively displaying color images having excellent display quality (in color and resolution) approximate to a ratio of 1:1:1 with red, green and blue.