The voice of the Big Bad Wolf was redubbed. In the original, he had a Yiddish accent. In the redubbed version, he was a Fuller Brush salesman, without the Yiddish accent.
It looks like it may be coming out on DVD! :eek: 
Zip-a-Dee-Doo-Dah Indeed.
Bumped.
Disney had a camera with a prism that allowed them to remove yellow, so for some of their movies they used a yellow screen.
Use of a Green Screen is something that came in with TV’s “ChromaKey” technology. Before that they used Blue Screens, and even earlier, yellow or orange screen (When King Kong broke through te gates in 1933, there was a sheet illuminated with orange light behind those huge doors). It was only important to have a color that could be easily identified and removed.