White Balance, The Colour Of Light

Our eyes automatically adjust to different lighting conditions as we move from place to place, and we don't tend to notice the subtle colour tints it carries. Nevertheless, these variations are much more obvious to the camera than to use and you may need to change your white balance settings to correct for them. For example, the light from a candle has a warm red/orange colour cast, whereas an energy saving light-bulb emits light with a cool blue/green tinge.