Cassock
The black clothing is the "sign" of the law. In this case, canon law.
Aztec Priests wore black-hooded cloaks,black robes and painted their faces and bodies and sacrifice people
To symbolize death. The life they have given to God. Also a few hundred years ago. The vadican made a standard way for priests to be recognized.
Catholics and Episcopalians are the only two denominations that call clergy "priests". Nearly ALL priests can and do wear street clothes when they are not working. This includes summer attire of shorts, shirt, sneakers/tennis shoes or sandals; and winter clothing of pants, shirt, and dress shoes. Episcopalians have female priests, so they also wear dresses, or skirts and blouses. When working, priests wear a black shirt, and black pants / slacks. )Episcopal priests also wear light blue shirts.) The black or blue shirt can be worn with a full band white collar or others prefer a tab collar that fits only in the front of the shirt. Over top of that, Catholic priests may wear a cassock or alb over the black attire and full collar. In services, priests wear a variety of different vestments over their black street clothing. Very colorful and symbolic vestments are worn for certain church holidays and to match the liturgical calendar. For example, purple is often worn for Easter.
a cassock is a gown worn by priests, deacons and often by the choir during church services.
The color of clothing has no relation to your health. If black clothing were unhealthy, Catholic priests would be sick all of the time.
I do not know what their mission was. The "Black Robes" were Jesuit priests from France that traveled in Canada (mostly in what is now Quebec and Ontario) back in the fifteenth century.
Roman Catholic priests are well recognized by their white collars and black clergyman suits or cassocks, although, some priests have chosen to put aside these identifying garments when not performing their duties and use secular clothes. Priests that actually serve the faithful of the city of Rome have their own particular garb, a cassock with red piping. Follow the links for visual examples.
Yes. Buddhist priests, Hindu priests, Catholic priests, Protestant ministers, Muslim Imams...
If you mean priests, no. There are no female Catholic priests
They wear Vestments while conducting the Divine Liturgy and the Sacraments.