It was my understanding that in the first couple years or so of the Merc Wizards, they were produced in gold. Although I have seen WD3 restorations done in dull aluminum (there is a beauty on ebay right now), I don't think it is technically correct...I could be wrong. But it wasn't long before Mercury went to that faded green paint that we all know and love.
Anyway, that is my understanding. If you are contemplating a paint job, do what will make you happy!!