Source? Based on everything I'm reading, the actual color of the Steelers uniform includes the color gold, not the color yellow.
To me, it seems that fans just THINK that its yellow.
Regardless, it would seem to logically make more sense to refer to a team by their actual official colors, as they define them. Its certainly not up to the fans to define what color to call a team.
Goldenrod? That would explain my allergic reaction...