I was reading a few pages back and someone mentioned the Steelers logo with its use of orange (yes, orange, not red) and blue, but the team not using the colors anywhere else in their brand. You all may know this already, as jersey aficionados, but if not, I'd like to clear it up. As a 35+ year season ticket holder, I've answered this many, many times.
The Steelers logo was not originally created for the team. It was the logo of the American Iron and Steel Institute, which was then appropriated by US Steel and used on its promotional materials. It can still be found on several old mills in western Pa. The original logo had the word Steel instead of Steelers and had yellow, orange, and blue hypocycloids. These were used to promote the attributes of steel: yellow lightens your work; orange brightens your leisure; and blue widens your world. The logo's meaning was later amended to represent the three materials used to produce steel: yellow for coal; orange for iron ore; and blue for steel scrap.
The logo has a great deal of meaning for people in our region, since most of us have steelmaking in our blood. Why the franchise has never really adopted any of the other colors in a meaningful way probably rests on simplicity's sake.
Like I said, I'm sure many of you knew this info, but I like to share.