While ceramic is much more scratch resistant than aluminum, Rolex initially could not continue to produce the two-color bezel used to distinguish between the day and night times of the second time zone, particularly the color red which could not be created satisfactorily in ceramic.
Although ceramic is much tougher than aluminum, Rolex couldn't easily keep making the dual-colored bezel that distinguishes between the day and night time zone, especially the red color, which proved challenging to create effectively with ceramic.