Editing

What you see is the difference between raw (and DNG) images and jpeg/tiff images. A raw image does not have a white balance yet, so you can set the white balance yourself. The lowest temperature you can set is 2000, but for images taken outdoors you will need something like 5500 if it was sunny, and even higher if it was cloudy. Indoors with artificial light requires lower values, but 2000 is extremely low so you will hardly ever need it. These are degrees on the Kelvin scale. JPEG and other rgb images have their white balance already applied, so you can only make small adjustments. That is when you will see the temperature as a slider that defaults to zero and can be set to positive and negative values.