This information applies to version(s): 1, 2, 3, 4, 5, 6
Digital cameras and raw conversion software offer white balance settings in the form of two variables: temperature and tint.
Internally, they translate temperature/tint settings into three coefficients that are applied to the red, green, and blue channels. These are two different ways of representing white balance; one is more intuitive for photographers, whereas the other corresponds better to what really goes on 'under the hood'. The conversion between temperature/tint settings and RGB coefficients is non-trivial; moreover, it depends heavily on the characteristics of the sensor. Every manufacturer and software editor applies its own proprietary algorithm.
To ensure consistency with what’s going on under the hood, Exif metadata contains the RGB coefficients instead of the temperature/tint settings. As a consequence, the white balance actually applied by DxO PhotoLab corresponds to that applied by the camera — but because the temperature/tint settings displayed in our user interface are derived from those coefficients using DxO's proprietary algorithm rather that of the camera manufacturer, they can differ.