I am restoring a 1971 911S and was wondering if someone could set me straight on the proper color/material for the under body of the car.

I know the wheel wells and arches get a light dusting the color of the car and the trunk and engine bay are painted the same. But what color/material is the main floor section under the car supposed to be ? Also the front suspension pan and support areas and the battery boxes ? Any infomation would of course be greatly appreciated. While this is not a concours restoration I would like to come as close as possible.

Thanks
David