Why a white bottom?

My Dad's 70-1/2 E/Stock Camaro had the firewall, bottom of the hood, and the underbody painted white for various reasons but mainly it was to reflect light. Some tracks he visited had very poor lighting at night, and when using only a drop light to work under the car, the light color allowed more light under the car as opposed to a dark color. (the car was a factory black car)The inside of the trunk and underdash were also painted white for the same reasons. He also painted the fuel tank white, so while sitting in those long staging lanes that were blacktopped, Bristol specifically, the white paint would reflect the heat from the pavement. Thus keeping the fuel cooler than if the tank was black. Just thought I would throw my two cents worth into this......Rat Pack...