their caps from black to gold with a black brim; they also introduced pullover nylon/cotton jerseys and beltless pants as part of their new uniform set (later to become polyester doubleknit). The Pirates became the first team in baseball to sport such a look, but it quickly became popular throughout the league, and the pullover style would become the prominent look of 1970s and 1980s baseball. The Pirates ditched the pullover style in favor of the traditional button-down style in 1991, one of the last teams to switch. In 1976, the National League celebrated its 100th anniversary. To coincide with it, certain NL teams wore old-style pillbox hats complete with horizontal pinstripes. After the season, the Pirates were the only team to adopt the hats permanently, alternating between a black hat and a gold hat for several seasons. The Pirates switched back to a brighter shade of gold for the 1977 season, and became one of the first teams to wear third jerseys, following the Oakland Athletics. Starting in 1977, the Pirates had uniform styles which included two different caps and three different uniforms: an all-black set, an all-gold set, and a white set with black-and-gold pinstripes. The pants, tops and caps could all be worn interchangeably for different looks; the Pirates wore four different uniform combinations in the 1979 World Series. The pinstripes came off the white uniforms in 1980, but the Pirates continued to utilize the three uniform set until the 1985 season, when the team returned to the straightforward home whites/road grays combination. The solid black cap with a gold "P" returned in 1987 and has been the team's primary cap ever since. After Kevin McClatchy purchased the team in 1996, the Pirates added a third jersey and utilized red as an accent color, including red brims on the team's caps. A sleeveless white jersey with pinstripes was worn as an alternate home jersey from 2005 to 2010, and a red alternate jersey was added for the 2007 and 2008 seasons. In 2009, the Pirates began wearing an alternate black jersey with a gold "P" at both home and on the road. From 2013 to 2019, the Pirates wore throwback uniforms for Sunday home games: the early 70s pullover uniforms from 2013 to 2015, and the gold top/black pants from the late 70s from 2016 to 2019. Since the 2015 season, the Pirates have worn an alternate