302 and C4 trans paint color? 1968

what color is the trans supposed to be?

Natural. A C-4 and C-6 would be Aluminum, A top loader 4 speed is Iron with an Aluminum bell housing and a 3 speed would be the same with the exception of an Aluminum tail housing.

Ford painted all engines Ford Dark Corporate Blue from 1966 model year through 1978 model year.