When I was a kid watching the reruns, I clearly remember one of the openings with the credits had "Hazel" coming out the front door to check the weather, then it starts raining and she runs down the street with an umbrella to take it to someone. I'm on Season 4 of the DVDs and that opening has yet to appear.

That rain opening is in syndication but IIRC is not on the 5th season DVDs. I think on the DVDs all episodes have the opening where they all get on telephone extensions.

isn't there about 6 different openings from season 1 to season 5?

Yeah, there are a lot of them. In season 1 there is the one with the cookies, and the one where the Baxters are returning from a trip.

I think there were a couple that were used only once. The re-filmed cookie opening was used once in the first episode of season 2, and an opening where the family is taking a picture was used once, also.

The cookie baking opening -- if I'm not mistaken -- also exists in a color version, which appeared when they did the one ep based on Hazel buying a color TV. (Season 1, Episode 6)

Yes it does. It appears to be the original version. My only thought on that would be they knew they were going to do the color episode, so they filmed the cookie opening on color film.

Then they re-filmed it for season 2 and either used it only once, or it was used only once in syndication--hard to know.

That rain opening is in syndication but IIRC is not on the 5th season DVDs. I think on the DVDs all episodes have the opening where they all get on telephone extensions.

Yes that would be correct.