Color of Paint underside

[6s2020]

Bolt on parts red-oxide was fairly consistent, much more than the undercarriage.  I would not use the same color primer as the undercarriage on those, the typical dp-74lf red-oxide is usually close enough for bolt-on parts.

Also, I didn't read the thread completely, but it's common for there to be a different color/shade of red-oxide up under the front frame rails extending to a line perpendicular with the face of the firewall.  The thought on this is the automated spray jets were not used for that part since the middle ones would have blown up through the engine bay opening.  It's something that most have never noticed or duplicated.  On some 65 cars with black primer on the belly, the front frame rails were sprayed red-oxide... further reinforcing the thought about the spray jets not turned on for the front part of the car.

+1  6S2020 is like what Charles has seen