The sepia scenes were lost in a fire. A black and white dupe has been used since and re-colored.
Interesting, I have a LD of Wizard of Oz from 1983 and the opening pre-Oz is black and white but the transition to Oz is sepia. Always wondered why some copies of the movie were sepia and some were grayscale
literally how they did that was for that specific shot whenever it transitions into the color what they did was get a double of Judy Garland, did her clothes and skin to make it look sepia, and paint the set of the interior of the house sepia that way it’s possible that it looks like a transition into a color world when in fact it’s not, it was in color this whole time it was just visual trickery (and the reason for the double is cause Garland was off camera for the sepia part of the shot, and after the double walked off camera then Garland came on wearing her colored clothes)