True color/appearance of the "Graphite, or Smokebox colors

[NW Modeling List]

As I look over my collection of steam power I notice that the Graphite  
or smokebox color is never the same on any two engines.
Graphite on a pencil is metallic.
I understand the graphite was powdered and mixed with linseed oil and  
painted on with a big crude brush.

Well, my specific question is what would that smokebox and possibly  
firebox color be if it were the mid 1930's?
Did that change by the 1950's?

Secondly, is either the Precision Craft Models Y6b, or Lifelikes Y3  
graphite correct?

I have seen a Sunset M2 factory painted and THAT smokebox was very  
metallic.  Looked like Testors "Steel" which is a flat, darker than  
"Bright Silver" silver.
Could THAT one be correct?






Mark Lindsey
N&W Historical Society
Stuck in the 1930's