Methods and apparatuses of operating an electronic device are provided. A display unit of the electronic device displays an image as a preview. A control unit of the electronic device differentiates a reference object and a target object in the image. The control unit determines a reference color of the reference object and a background color of the target object. The control unit adjusts the background color of the target object so as to correspond to the reference color of the reference object. The control unit sets the background color of the target object.