There are now several white spots appearing on Ceres as Dawn makes it’s final approach to the dwarf planet. Any knee-jerk expectation say that there is merely a brighter material beneath the surface that was revealed by ancient impacts. Why the surface is darker and the underneath material is brighter (see Iapetus) would be a mystery… but perhaps they still may be related to the active geysers scientists have previously predicted due to data provided by The Herschel Infrared Space Observatory.
We shall soon see.