1970 Chevelle Atlanta Body Shell Primer Color?

[1972convss454]

I am restoring a mid October 1970 Chevelle built at the Atlanta Lakewood assembly plant.
My question is what color primer should be used on the body shell?
Attached are pic's from the underside of my car and the color appears to be a gray color. Is this consistent with other Lakewood cars? I appreciate your help, thoughts and insight.

[SS427]

It is a greenish grey though I have never worked on any as green as what your photos show but yes that is correct.

[1972convss454]

Thanks Rick for the info. This is my first Lakewood car. The color almost looks on the Blue side vs Green. I cant hear or smell and can only see out of one eye. lol I will match it as close as I can to what I have.
Thanks Again!

[SS427]

I would definitely try and match what you have. Primers were not a unique science when it came to color matching as long as they performed what their intended purpose was. Since you have photos of the original primer, I would certainly reapply that color.