Pacecarjeff,
Here are a couple of pic's of my diverter valve. They may give you a better look at the color. FORTUNATELY, I found a complete, correctly date coded, survivor smog system including the valve, pump, hoses, hose clamps, etc. My phosphate is a medium gray color. UNFORTUNATELY, several years ago had an overcharged battery spew acid and spot the cover and "GF" stamp. To say the least.....I was majorly P.O.'d. I rubbed the unit with oil and wiped it off to prevent any further corrosion.
Hope this helps and good luck with your plating.