King of the Hill - Magic Shorts
This slip up happens in the episode where Hank is trying to increase his sperm count. Hank is sitting on a stool in the garage talking to Bobby. You can see Hank wearing brownish shorts. Then hank stands up, and it switches to a view of Bobby’s face. Then is shows hank walking to his left. Look now, his brown shorts magically change into blue jeans. Then it looks at Bobby again. Then back to Hank. Now look, his blue jeans magically turn into brown shorts again.