An instruction of an electronic device is provided. The instruction of the electronic device, when executed by a processor, causes a display panel to be operated using one of a first gamma set corresponding to a first operating frequency and a second gamma set corresponding to a second operating frequency, each of the first gamma set and the second gamma set comprises gamma voltage values for each luminance and gradation, the first gamma set and the second gamma set include the same gamma voltage value in a first gradation range of a first luminance so as to have the substantially same optical characteristic when the operating frequency changes, the first gamma set and the second gamma set include the same gamma voltage value in a second gradation range of a second luminance, and the first gradation range and the second gradation range are different from each other.