Half B+W and Half in Color

I remember seeing this movie when I was 8 years old in Miami and I vividly remember that it shifted from b&w somewhere in the middle to brilliant color (maybe early technicolor?) - I believe at the point of one of the big dance scenes. I can still see Ginger. I had never seen "Oz" at this time in my life so it could not have been personal flashback.
Does anyone else remember this?? or could this just have been a fluke of the theater tech at the time??