I don't know so much about the '60s, but in the early '70s, said jeans were required to be Levi's, "Big Bells" preferred. Any deviation from this norm was only grudgingly tolerated.
Back in my "disaffected youth" days, tromping around Northeastern U., I used to wear a t-shirt that had a big picture of Vladimir Lenin on the front, over that it said "Surf Russia". I used to get scruffy, non-bathing commies come up to me all the time, wanting to talk about "revolution". I'd tell them "Back off dude, I voted for Reagan. I just wear this shirt to annoy people like you." Strange that back then, living in the "Peoples Republic of Mass", the only way to rebel was to denounce commies and embrace conservative values.