How to Change Your Digital Camera’s White Balance
Digital cameras use a process known as white balancing to tell the camera what combination of red, green, and blue light it should perceive as pure white, given the current lighting conditions. With that white-identifying information as a baseline, the camera can then accurately reproduce the other colors in the scene.
Although white-balance controls are designed to improve color accuracy, some digital photographers use them to mimic the effects produced by traditional color filters, such as a warming filter. As this figure shows, you can get a variety of takes on the same scene simply by varying the white-balance setting. How each setting affects your image colors depends on your lighting conditions.