How did they change March’s skin color during transformation scenes?
Every time March changed from Jekyll to Hyde initially you visibly see shadows form around his eyes and cheeks as well as his lips darkening and other skin tone changes. This is accomplished in the shot, not as some kind of blurry fade as is more typical in older movies. Seeing this in a modern movie you wouldn’t think twice about it, but this is 1931 and I’m puzzled as to how this was achieved in front of the camera in an unbroken shot.
Does anybody know how they did it?