There certainly is a lot of blather posted will supposing to answer your question and solve your problem. It is a basic question and an even more basic problem. In fact not even a problem at all.
This is the modern day United States of America not olden days Scotland. You can wear what you want and you don't have to explain yourself to anyone. As long as you don't tell people you are from a specific clan when you aren't you can wear any damn tartan you damn well please. If you like the looks then wear it. If you want to find a friendly clan to join and you like their tartan then go for it but most important is "to thine own self be true" and wear what the hell you want to and the devil with others opinions.