Just to add something, me and a guildie dropped the world boss on Alderaan today, and he did NOT drop the white colour crystal - He dropped the two other epics that he was listed to drop on the DB sites, but not the colour crystal. Whether or not this is a case of he has a chance to drop it, i do not know, but it is looking more and more likely that these 'rare' colours are coming from end game content, unless anyone has a confirmed schematic drop from somewhere.