Buddy, I have been researching this topic for years, but had put it on the back-burner for other topics until I read this post. Personally I have yet to see any 67 built in the LOS plant using red oxide primer as its base prime coat, and very few NOR built cars until 1969. What you are seeing in the picture of the floors on the car at Team Camaro is the body color overspray and not red oxide primer. I just sold an 01C LOS car that was red and the floors looked just like this one, covered in red body color not red oxide primer. The primers on that car were all greys: dark grey (black) base prime, with lt.grey being the topcoat sealer. Why I think most would think that this is red oxide primer is that when the red overspray of the body color hits the darker gray it will turn it an orangish/brown color from where it bites into the undercoat. If the owner of that car waxed those red areas he would find it is body color. Red is the hardest body color to distinguish from red oxide primer in 67 & 68 is those reds had an orange tint to them more than the 69 Garnet Red.
stated above, usually the overspray on the floorpans of the LOS cars was heavy as compared to the NOR built cars, so the picture of the car on Team Camaro can be confusing. Another good place to look for the primer overspray is in the shock tower area. The picture below is from the 67 I am restoring now, it is an LOS built car and no red oxide primer used at any time. Take some pictures of the underside of your package tray area, but set your flash to use the "red eye" reducer so you do not get any harsh light reflections. Doing this should show you the colors of primers used on your car. I had always thought that the topcoat sealer color had something to do with the final color of the car, and I am still leaving that option open. The first cars I have found with red oxide or "ruddy brown" primer/sealers to be predominantly used were in 69, but I have seen just as many with dark grey/black. I do not totally agree with John's statement in the article that red oxide was the base primer, at least not for all years and both plants. I have seen more cars with dark grey (black) than any other color for its base primer in the first gen Camaros.
To answer your latest question, the dark color is the primer surfacer first applied after the phosphating is done. What color is your car? Also what is the exact build date 02? ....................RatPack.............................
*** Anyone with an urestored car that has not had any restoration work to the undercarriage or floors other than being washed, I would like some pictures for a future CRG article regarding this topic. Please send me a private message and I will give you my email address where to send the pictures to. All years of 1st gens are wanted, including Firebirds.