I think all the Chevrolet Advance Design truck grills were painted from 1951-1953. (Korean War/Conflict - chrome/chromium "went to war"?)[/url]
Outer grill bars on painted grilles were body color with white or ivory inner bars. I'm pretty sure 1952-1953's had painted bumpers and hubcaps, but not necessarily grilles. I can't confirm any '51's had chrome plated grilles, but my '51 definitely had a painted grille (Omaha Orange outer bars/Waldorf White inner bars).
I've seen a grille that had chrome powder coating on it. Looked pretty similar to chrome plating.