Resonances of the so-called "Rob Roy" tartan?

[Old Building Prof]

I have been wondering about the so-called "Rob Roy" tartan--the basic red and black tartan that seems to have been appended to Clan MacGregor. This particular pattern seems to occur fairly frequently in early portraits, of everyone from Norman MacLeod of MacLeod (aka the Wicked Man) to Niel Gow. Historically, in practice, was it actually always a universal tartan? The appellation "Rob Roy" seems a 19th century invention, but does it carry that association to many today? Among contemporary tartan wearers, what association does this one carry? What is one likely to think of someone sporting it?