Hardware color question for radiator/shroud

[440plus6]

Need help/guidance!

In preparation of installing my recently Glen-Ray restored radiator and repop shroud in my 69 Charger, I purchased a hardware kit from AMK for securing the radiator and shroud as I wanted correct fasteners. In comparing the new bolt kit to the stuff I removed, several of the old bolts/nuts are mismatched. My question is this, every bolt/nut I removed had been painted black previously, obviously my rebuilt radiator is black, is the correct factory finish for the hardware black or natural? Appreciate all of you as always and hope to get this project buttoned up.
Thanks

 

[Longknife]

I believe all the original bolts had a black oxide coating.

 

[YY1]

They were black on my 73, but not painted as the post above states.

 

[gtx6970]

black oxide finish. 1/4-20 thread . with a 1" free spinning washer

Most common head markings was a N on the face

 

[Islandkent]

Nuts holding the shroud to the rad should be zinc. 1/4 20 flange nuts. For 1969

 

[440plus6]

Thank you to all that commented! Appreciate the knowledge