Dittrich,
Your stamp is a #65 that is very sulfuretted (discolored/darkened/oxidized). So, it is impossible to say what the original color was. I think I can see a small amount of the original color behind Washington's head, but not enough to evaluate the color.
See "Sulfuretted" at the link below:
http://www.uspcs.org/the-1851-1860-...-10-and-10a/