When I striped the paint on my 1962 Nova convertible I found factory red oxide on all interior sides of the sheet metal; floors, top well, kick panel, inside firewall. The exterior body was medium/dark grey. Including the underside. Original colors are black exterior, red interior. A 1962 Nova parts car I had was light grey throughout. My moms. 1962 Pontiac was red oxide throughout. I also have a set of 1963 Nova doors that are also red oxide.