Color for Radiator support & areas behind grille on 71 Scamp

If it was done at the factory, they usually only painted the parts you can see thru the grille. But this varied wildly, and may or may not have been done on certain days, and/or depending on the definition of "dark colors". Also, there was no masking done at all. I'd paint it black... but I'm a person who hates seeing body color thru the grille.
True that. They were painted from below (in a pit) and they used, for a better word, thinned undercoat sprayed out of a weed sprayer nozzle type sprayer. (not paint from a paint gun) Most got it regardless of color but the darkest colors may or may not have got it. There are guys here with original light colored cars that didn't get coated at all. Spray it flat black and you will be good.