I think there is auto white balance that adjust the wb automatically if the picture changes in color, but also you can take the picture from white paper in the right lightning and get it right that way, or in magic lantern you can manually set the right kelvin reading. If I take the picture, it won't change my WB in video or picture modes. I guess this is said to be manually too(?)
I also changed to my SDHC card instead of SDXC card which had ML 2.3 too and the same problem occurs.