Sports teams are known by their logos, NFL teams included. The bright and bold colors are meant to stand out so that no matter where you watch a game, you can always tell who is whom. The Pittsburgh Steelers are no exception in this way. The bright stars or "hypocycloids" of the team's logo have a deep meaning to a specific area of Pennsylvania.But there is something about the Steelers that sets them apart from other NFL teams. Theirs is the only uniform to have their logo on only one side of their helmets. But why do they only have one decal? There's actually a very simple explanation for it.Why do the Steelers have only one decal?According to The Los Angeles Times, that's just how it is. "Dan Rooney [whose father, Art, founded the franchise] told him to put the decal on the helmet, and he just went ahead and did it and put it on the right side only," said Joe Gordon, the Steeler's former communications director. "Dan was not specific as to whether he wanted it on both sides of the helmet or just the one side. So once it was done, he never changed it."The article also mentions that a second logo could have been added onto the other side of the Steelers helmets but that the topic never came up in conversation. Although the team does have another logo. The word "Steelers" in black and yellow is also associated with the team. It can also be seen on some merch, the team's website, and it's proudly displayed along with the circular decal.Although most NFL teams do have their logos on both sides of their helmets, some teams don't have logos at all. The Cleveland Browns are simply known for their particular shade of brown. And the Cincinnati Bengals have helmets covered in black and orange stripes.What does the Steelers' logo mean?The LA Times also says that the logo originally belonged to The American Iron and Steel Institute. According to its website, The Institute was founded in 1908 after a large amount of growth in the industry. \n\nAfter being called The Pittsburgh Pirates for some time, Art Rooney changed the name to Steelers because it was the most suggested during a contest he ran, according to The Sun. The current name honors the "steel mill heritage" of the area.The colors of the logo: blue, orange, and yellow, also have their own meanings. According to The American Iron and Steel Institute, "Steel lightens your work, brightens your leisure, and widens your world," and the colors represent those ideas.In addition to that, they each represent the materials used to make steel. Blue is for blue scrap, yellow is for coal, and orange is iron ore. However, the Steelers use a red hypocycloid instead of an orange one, so they kind of made it their own.