Take three photos of the same scene with different White Balance. Use the Daylight, Cloudy and Florescent options.
As you can see, the camera is quite smart at getting the White Balance correct on Auto.
However, if you want to accentuate the mood in your photo, you may use the White Balance. Perhaps set it to Shade, and get much warmer tones - and make your scene look like a hot summers day. Or use Fluorescent to make it look cold and bleak. Obviously, the White Balance should match your subject too. A cold meadow of flowers or a warm snowscape would probably confuse the viewers of your image.