Answers I got last night (that I think are new):  (paraphrased from memory) Written question: Is VenDell changing suits or is the suit changing colors?  VenDell is changing suits.   No Nalthis/breath connection after all. :-( -Are all the red-eyed characters influenced by the same shard?  No, but the red is significant.  (it has meaning in the cosmere) quick theory: Red indicates corrupted or co-opted investiture Unfortunately, that takes some strength away from the "all those re