Light has a temperature. The color characteristics of visible light are determined by its temperature. Without spending time on the physics, one can develop an intuitive understanding of the relative warmth or coolness of the light by thinking of the light source. 

On one end of the spectrum is candle light, which produces a very warm yellow – almost red tone. On the other is deep shade of the outdoors – which has a very cool or blue tone. In the middle is broad daylight. 

Your camera’s auto white balance setting will do a good job of determining what the color context of the scene you’re shooting is when there is something white in the picture frame – a cloud or the side of a white building. 

You’re better off manually setting the white balance (WB) to the icon that best describes your lighting circumstance when your image contains warm or cold toned subjects – a red fire engine, or a field of blue flowers. 

Often, if you’re shooting inside, you may have light from the outside streaming in through windows competing with the light from incandescent bulbs. In this case, getting an even color balance for your image can be a nightmare. If you’re looking to capture compelling colors without competing color casts, make sure you have light coming from only one source.

Light from the window is creating a blue cast on the left side of the subjects face, while yellow light from an incandescent bulb is falling on the right side.

For accurate color make sure you’re only using one light source, then tell your camera what kind of light you’re in by manually adjusting the white balance setting on your camera.