Imperials for sure. I bought them as a kid in the 80s. Back then we called them rainbows because of the different color stripes. I can't believe I actually wanted these as a kid lol, they are so common now but back then they weren't seen much, at least for me.
Al, is it the color combo that puts them back to the 70s? I do remember buying these 3 color striped ones in the 80s but might not have been the same colors, or they could have been stock that was still being sold?