Dont forget the jump in pinball here, Wizard of Oz was about dorothy going into a colour world... pinball will have a colour display! from the world going for black and white to colour in the movie. Orange to colour in pinball 
I like this idea
start the game off with the display looking like a boring old orange DMD, then, get to OZ, and the display bursts into color
Is this actually locked in as a design feature or has the idea spawned from this discussion??
Its about the coolest thing ive heard for a pinball for many years... what a great idea!
