Quick Question

[haukehaien]

Actually, I've run into a similar thing. My first kilt is a fashion tartan, red, black and gray. (You can see it here.)
I was wearing my new SWK Gordon to church and someone asked me if it was a new kilt. I said it was, and as I passed on, I heard another person say "Yeah, his other one is red, more of a traditional plaid."

I think that the common usage of Royal Stewart in advertising and so on has really shaped a lot of people's perceptions of what "tartan" is - I suspect most people imagine a red tartan when they think of tartan.