Luke 16:19 There was a certain rich man, which was clothed in purple and fine linen, and fared sumptuously every day:
"A certain rich man" refers to a particular one, he is prominent, likely he is well known.
Clothed in purple and fine linen is what priests wear. We already know he is rich and that rich people wear fine clothes. So we don't need the term purple to tell us he is rich. Instead a rich man might wear clothes of any color, but to be specific with "purple and fine linen" that is quite distinctive for a priest. However, the Jewish priests were primarily blue and fine linen.
I thought this refers to the Pope who wears purple, but he only wears purple during lent and advent. He had on a purple sash during Easter service.
Now "fared sumptously" is a very interesting expression. The word for fared is often translated "Merry", "happy" or to make merry. So often associated with a party or celebration. Sumptuously means magnificently or splendidly. So it is not indicating a kind of gluttony, rather it means to live like a king. We have a picture of a priest, living like a king, and not any priest, a certain priest, a particular one, a famous one, a priest the whole world knows.