Whitebalance

Different sources of light produce light of different nature. The human eye compensates these differences quite good and we recognize i.e. a white surface as white under most situations. With analog cameras you have to use the right film-material depending on the available light or you can compensate with color-filters.

Normal film for daylight needs a clear sky and brightly illuminated objects for proper colors. Under a clowdy sky or in the shadow images getting blue, red under artifical light and green under neon.

Within the digital world the whitebalance is responsible to compensate different light conditions. In auto-position your camera always tries to guess the right whitebalance depending on the image taken. To make this work, the camera must have a gray or white object somewhere within the scene and must properly detect it. If there is nothing neutral in your image, automatic whitebalance can't work as expected:

This image is a panorama composed of five single exposures with tight transitions so the problems are clearly visible. Did you guess the right cup is yellow and not green? And the color-changes of the wooden folding rule are obviously too.

Therefore I mostly never use auto-whitebalance, so that images of a sequence match in color. You can use one of your camera's presets or make a manual whitebalance on a neutral surface. The correct panorama with a fixed, manual whitebalance would look like this: