1. A recording medium causing a computer to execute a color adjustment program used for an image quality adjustment comprising: identifying selected adjustment type that represents either shift process or centering process; assigning weights to adjustment amounts of colors included in an adjustment range according to the selected adjustment type, a positional relationship with a target color in color space, and an adjustment amount of the target color, when information about the target color to be adjusted, the adjustment amount indicating an amount of the color adjustment made to the target color, and an adjustment range for deciding a range of colors to be adjusted along with the target color are input; calculating colors after the adjustment for the target color and the colors included in the adjustment range according to the weights; and drawing a three-dimensional region corresponding to the calculated colors in the color space; wherein the colors included in the adjustment range are moved in a same direction as an adjustment direction of the target color by the shift process and wherein the colors included in the adjustment range are moved in a direction toward the target color by the centering process.