Discolored rockers and springs on #4 cylinder

[scilicet]

I am in the process of replacing the intake manifold gaskets in my 2001 Grand Prix with the 3.8l V-6. The front valve cover gasket was leaking so i pulled it and figured I'd replace the rear as well for good measure. When I pulled the rear valve cover off, the rockers, springs for the #4 cylinder had a peculiar red discoloration. It wipes off with a dry rag, but I have no idea what it is. Any ideas would be greatly appreciated

[FordMan77]

Probabaly just additives in the oil reacting the to metal. Take a pic if it's really strange so we can see.