Alco 251 engine factory paint color ? - Model Railroader Magazine

Once again, I humbly call on those with knowledge. Thank you.

What color paint would Alco engine paint be ? The kind they spray down the engine block,covers and pipes etc. 

Just picked up two Phanton Hobbies 3D PROTON printed  Alco 251 18 cylinder engines . This will be a totally new material to work with. Kinda excited about these new engines.

Either flat car loads or emergency power or stuck inside a shell or whatever. The ebay seller also has HO EMD 567 18 cylinders engines. He did have other Alco & EMD engines available but they sold.

  Just passing info on.