Sounds like maybe you got a bad copy where the color signal conked out on it’s way to the recorders. Tapes were mass duplicated and I doubt every tape was quality checked before being shipped out. I once even got a movie that was not the one on the box or label!
O, so you’re the guy that bought that snuff tape I labeled as the three hour cut of Dune. Sorry about that. The prank was funnier to me then. I’m a changed man now.