I guess it depends on what settings are on your camera. What kind of camera do you use. I have a Canon 50D and it has settings for sun, shade, clouds, tungsten, fluorescent, average white balance and a custom white balance. Try shooting the same object with different settings to see the various results.
Do you have a specific question?
Here is my thoughts.
I am just going to simplify things for you from my perspective.
The most important thing I ever learned how to do was to do a pre-white balance on the camera while shooting out doors using the gray card.
If you google youtube on how to white balance your camera you will get a few videos that will walk you through it.
In my mind that will give you the closest image from what you eyes are seeing.
Seldom do I bother to use the cameras presets unless I have to take a quick shot and I don't have time to experiment.
Using the Kelvin temperature scale can become very complicated and is really for in my opinion scientist.
Most times just run it on auto if you don't have a gray card. Most times when I am in the studio I set white balance to auto.