PITTSBURGH -- When you think of Pittsburgh’s sports teams, two phrases might come to mind: “City of Champions” and “black and gold.” The Steelers, Penguins and Pirates all proudly wear black and gold in Pittsburgh, the only city in the United States in which all the major professional teams share the same primary colors.

It wasn’t always that way, though. The Pirates once wore red and blue, not the city’s modern signature colors. Let’s look back for a brief history lesson on how the three most well-known teams in the city of Pittsburgh, including the Pirates, came to wear black and gold.

It all starts with the Pittsburgh Pirates. No, not the Pirates of Major League Baseball. Not even the Pirates of the National Football League, the name the Steelers first went by from 1933-39. This is about the National Hockey League team known from 1925-30 as the Pittsburgh Pirates. Although it should be noted that the hockey Pirates were, in fact, named after the Pittsburgh baseball club that also inspired the football team’s original name. (Got all that?)

The NHL’s Pirates sported black and gold uniforms to match the colors of the city flag and city seal. Those colors in the city’s coat of arms are drawn from the family coat of arms of William Pitt, the Earl of Chatham and the city’s namesake. The hockey team eventually switched its colors to black and orange, moved to Philadelphia and became the Quakers before folding.

But those short-lived Pirates were the first Pittsburgh team to wear black and gold, the colors that now serve as a source of civic pride, and their history in those uniforms would later help permanently round out the trio of black and gold-clad teams 50 years after they left town.

The Steelers present a much simpler story. The city’s football team has sported black and gold since its inception in 1933. The only time the Steelers veered away from wearing Pittsburgh’s colors was in 1943, when they temporarily merged with Philadelphia to form a team known as the “Steagles” clad in green and white, the Eagles’ colors.

As for the city’s original Pirates, the baseball team now synonymous with black and gold? They wore red, white and blue in their early years. They began introducing black and gold in 1947, according to The Pittsburgh Press, and first wore their present-day colors on their uniforms in 1948.

“Not content with revamping Forbes Field, the front office and even the playing roster, General Manager Roy Hamey and Manager Billy Herman have even worked out a new deal on the home and road uniforms,” read a Pittsburgh Press article from Jan. 21, 1947. “The Pirates’ colors now will be gold and black, colors of the city of Pittsburgh itself, instead of red and blue, although the gold will not show on the uniforms.”

The introduction of gold to the uniforms can be found in a handful of archived newspaper accounts from Jan. 4, 1948, although the news was overshadowed in two articles by the announcement that weekday home games and Sunday doubleheaders would begin at 1:30 p.m.

From The Pittsburgh Press: “A few changes will be made in the Pirate uniforms for 1948. The word ‘Pirates’ will be spelled out across the shirts in block letters of black, bordered with gold. The numbers on the backs of the shirts also will be black, bordered with gold. Each player will wear black stockings, with three bands of gold encircling the stockings.”

From the Pittsburgh Sun-Telegraph: “For years the Pirates have been singled out as a well-tailored team. In this connection the owners have decided to add a bit of splash in the way of diamond livery. City of Pittsburgh and Pirate colors of black and gold will predominate in the new uniforms.”

The Pirates have worn black and gold ever since. It was their success winning two World Series championships in those colors in the 1970s, along with the Steelers’ Super Bowl dominance during that decade, that eventually spurred the Penguins to adopt the city’s unifying color palette.

The Penguins wore blue and white from 1967-80, but in early January 1980, they wanted to align themselves more closely with the Steel City’s thriving Pirates (fresh off a World Series victory in ‘79) and Steelers (weeks away from winning their fourth Super Bowl). Word spread that the Penguins would follow suit and switch to black and gold.

The team’s impending color change was the source of such inescapable speculation team that The Pittsburgh Press sought to shoot it down -- inaccurately -- in the opening paragraph of a story about the Penguins’ 5-3 victory over the Canadiens on Jan. 3, 1980: “There is no truth to the rumor that the Penguins will change to black and gold uniforms. And last night they proved the uniforms and their color are less important than the men inside them.”

Four days later, the Pittsburgh Post-Gazette observed that, “No, [the Penguins] did not break out in black-and-gold uniforms. The rumor that has them switching to black and gold lives on.”

Three days after that, the Penguins announced they’d be joining the Pirates and Steelers by switching to black and gold uniforms. “Black and gold has become Pittsburgh,” team vice president Paul Martha told The Pittsburgh Press. “And the Penguins are Pittsburgh.”

The Boston Bruins tried to prevent that from happening, arguing that black and gold belonged to them and protesting the Penguins’ switch. NHL president John Ziegler denied the Bruins’ request, however, in part because black and gold had previously been worn by another hockey team in Pittsburgh’s history: the Pirates.