Question: Rotor Blade Colors

"OUCH"

Most the Huey Main Rotor and Tail Rotor blades I've seen in early 70's to early 80's were Olive Drab. They may have been black on the Charlie models but I didn't work a whole lot on them. We had a couple that had white painted on top of one blade, Surfer and Ace of Spades.  I had seen a few sets of blades that were about the shade of the old Pactra Flat Green similar to interior green in the late 70's.   I don't know anything about H-34 blades but you couldn't put a Huey M/R blade on upside down, the mounts won't line up if you tried!   T/R blades were a different matter.   I've seen a couple mechanic's put the T/R Hub and blades assy on the shaft fliped so the "pre-cone" was towards the fin and not away.  By the time I walked over they had realized their mistake, the blades had contacted the fin.

 

I don't know about all Navy helos, but the SH-34s were painted grey on top, black underneath. This was supposedly to help prevent putting the blades on wrong side up.

You have to be a little more specific on what you want your end product to be.  Colors will vary by service depending on the era.  Only thing I can think of that would be silver/metallic/lt gray would be the rotor head itself (between the individual blades) and again that would depend on the era, service, etc.

Army helos usually have black or OD blades.  It was also common for blade tops to be painted OD green and the underside black.  Some had one blade top painted black and white as well for high-vis during formation flying so aircraft above could see them. 

The yellow tips are 6 inches in from the tip, both top and bottom.  In 1/48 scale, that equals about 1/8 inch.  

The tail rotor could be olive or black as well.

Usually Navy helos have gray blades.  I have not seen steel or other color blades.

As far as I know the rotors are black. The tail rotor might also be olive drab.

Huey's rotor blades are made of an alluminium alloy, primed (zinc chromate) and painted. So  if you want a weathered effect you coud have some bare metal and zinc chromate showing in selected spots (salt technique?).
The black would also be faded by sunlight to a dark gray, more than actual black.

This thread might help, too.