1. A method for calibrating an automatic white balance (AWB) of a sensor of a digital system, the method comprising: capturing an image of a test target under a natural lighting condition, wherein the natural lighting condition is one selected from a group consisting of outdoor sunny with clear sky, outdoor shade under sunny conditions with a clear sky, and outdoor with a cloudy sky; generating one or more first color histogram reference from the captured image; and outputting automatic white balance (AWB) configuration data for the digital system, wherein the AWB configuration data comprises the one or more first color histogram reference and a one or more second color histogram reference generated using the test target under simulated lighting conditions, wherein the one or more first color histogram reference and the one or more second color histogram reference are adjusted to compensate for the difference in characteristics of another sensor.