A color correction method and a color correction system that executes the color correction method are provided. A correction image is projected on a projection screen based on a predefined value. A single frame of the correction image includes multiple regions. The multiple regions include multiple hue regions with different hues and multiple lightness regions with different lightness corresponding to the hues, or the multiple regions include multiple gray-scales regions with different gray-scales. A captured image is obtained by capturing the projection screen. Optical information of the captured image is detected. The optical information is compared with the predefined value to obtain an uneven color region that does not conform to the predefined value. The uneven color region is adjusted so that the optical information of the uneven color region conforms to the predefined value. The time for color correction can be greatly reduced accordingly.