Having grown up when vinyl tops were the thing to have and stripes made it a muscle car. I have never heard of anyone refering to a car with stripes to make it a triple.
IN MY BOOK IT ALWAYS meant Black car, Black interior and black top, whether vinyl on steel or a convertible
I just posted about a triple green 69 SS Chevelle I owned for a few weeks, green ext., green cloth interior and green vinyl top.
But everyone one can say what they want, but if I see printed Triple it means Body, Int, and Top
I like triple Black cars but don't want one, a TRIPLE WHITE I would like to have.