I've come up with some comments over the years, being a Viking fan in Wisconsin and such.
"Aw...there's something wrong with your jersey...you should really get your money back...it's odd that they used the wrong color and logo."
"Isn't purple the color of royalty? The first thing that green brings to my mind is grass, and people step on that with their disgusting feet."
"Why don't the Packers have a REAL mascot? Does a giant "G" come out and dance at games?"
I have many more, but they apply to specific people, so I wont use them.
Lets hear some of the ones that others have come up with too!