Hi James,
In the era of the
"Hog", operational UH-1 rotorheads displayed an almost oxidized appearance, near camouflage grey, and steel colors on the actuator levers and rotorshaft, with black or dark gray boots....
Again, during the Hog era, rotors on the ones I saw had flat black undersides, and some hue of OD on the topsides...
Also, aircraft exposed to hostile fire, many times painted either one or two white stripes, longitudinally, across the mid part of the upper blade in order to make the aircraft visible against the jungle canopy to aircraft overhead.
Take care....and make sure to take some pictures!
Frank