Apart from the cockpit, which was chromate green, the zinc chromate paint used on Thunderbolts was very yellow. I've got half a dozen wartime colour shots showing this, of which the one below is the clearest. Also I found a couple of written references to the yellow colour and even this colour swatch.
Be careful if you are looking at today's P-47 warbirds. They've probably been repainted lots of times since WW2 with whatever chromate paint was either available or FAA approved.