Unlike the other episodes, I suspect CBS DVD couldn’t find the original 35mm negative for this episode, so they had to resort to using a more faded and beat-up 16mm tv print for their DVD transfer. They probably didn’t want to pour a lot of money into cleaning up an already-crappy print, so they went with it as-is for the dvd and digital releases.

MANNIX had a similar issue with a couple of episodes in seasons 7 and 8 that had a similar beat-up look to “Six Kilos” on dvd.