Above are two versions (two interpretations) of the same photo, the left hand side is taken with tungsten white balance and the right on Auto white balance. Tungsten WB turns the white light source to blue.
Here I have used artificial light, two flash one gelled blue on the background, the other gelled orange to make it the same colour and temperature as tungsten light. Set the camera to Tungsten white balance and the tungsten gel, which is orange turns the flash to white and makes the blue background light bluer still.
Above is another example, this time with natural light in the background and flash gelled for fluorescent light on Vicky. The gel turns the light green but when I change the camera to fluorescent white balance this makes the green light white. What is actually white light in the background becomes magenta coloured.
Above is a similar example this time with the light source gelled to orange, and the camera set to tungsten white balance. This turns the orange light to white and turns white light to blue, the colour on the right side of Vicky’s face is caused by natural daylight from a window behind her.