I know that the driver now will set up the default ambient color, even if it's not specified in the scene, but I like that it's visible to the app developer, too (like how we pulled the creation of the default camera out of the driver and put it in `scene.vwf`.  I wouldn't change anything that you've done in the driver, but I would leave the default value in `scene.vwf` so the user can see an example of setting the color and can understand why it's the color that it is.