code: public RotateOperation fillColor(int red, int green, int blue) {
          this.fillRed = red;
          this.fillGreen = green;
          this.fillBlue = blue;
          return this;
      }
docs: Set Fill color.
  
  @param red   Red channel's value.
  @param green Green channel's value.
  @param blue  Blue channel's value.