1. A color processing apparatus, comprising circuitry to: acquire bitmap data of a color chart for generating a color conversion table, the color chart having a grid of color patches that gradate a color, each color patch being uniform in color value; acquire first colorimetric values for each color patch in the color chart of the bitmap data; obtain a scanned image of the color patch by scanning a printed output of the color patch; acquire second colorimetric values for each color patch in the color chart of the scanned image; analyze each color patch in the color chart of the scanned image to determine a distribution of pixel values in each color patch; determine whether or not the color chart of the scanned image is defective based on the distribution of pixel values in each color patch in the color chart; and in response to a determination that the color chart is not defective, generate the color conversion table based on the color chart by associating the first colorimetric values with the second colorimetric values.