Herewith the Enterprise Products advertising page from the Newton K Gregg reprints of the 1943 Car Builders Cyclopedia showing what I presume is your car.
I can tell you with some certainty it is black because the half tone images of other cars known to be red are gray to the eye.
Much later in the 1960's Southern adopted new paint schemes with oxide reds - I am not expert in which cars were repainted -- if interested you could contact the Southern Railway Historical Association here: www.srha.net/
Hope this helps.
C Rooney