I just got season 1 of I Dream of Jeannie on DVD. I've seen the first four episodes, and they have a different theme song than the one I've always heard. Was Season 1's theme different originally, were just a few episodes different, or was it changed for the DVD release?

The first season of Jeannie has a different theme song. The more familiar theme took over starting with season two and color episodes. In the first season, I believe episodes 1 thru 8 have opening credits with narration and live footage. Starting with the 9th episode is where the animated opening credits took over that everyone is familiar with. Which season one DVD version did you buy? Original black and white or colorized?

the colorized version

The black and white version is better, that's the one I have. The first season of Jeannie was filmed in black and white, that is how it's meant to be seen. None of that colorized junk for me.