Question: What is the name of the Catholic cleric's skullcap? The Pope wears a white one, Cardinals wear a scarlet one, Bishops wear a purple one and priests wear what color if they wear one at all?
Answer: a zucchetto. Priests wear black, if they do wear one.
Read more: http://catholicnotebook.blogspot.com/2010/02/does-pope-wear-white-jewish-yarmulke-on.html