Union Pacific #844 shade of gray used on the smokebox

[BOBDDS]

I have an Athearn Genesis HO Big Boy that I have renumbered 4014, but I am looking for the current shade of gray that UP uses on #844 smokebox.  About the closest shade I have found in my paint stash is Floquil Weathered Black. Any ideas or does anyone know the actual shade? I also know that it is a flat finish.

[ndbprr]

Well I don't know for certain BUT due to the heat from the exhaust gasses and steam going up the stack from the smokebox most railroads used a graphite paint. It would age darker from the cinders and smoke but that would be a good starting color. Several paint manufacturers have graphite in their lines of paint.