I've never seen PBRs in service without having at least the framework for the canvas tops in place. Gotta remember, in the 'Nam it rained on a daily basis, in some places you could set your watch by it...
As for seeing PBRs in black, I've seen them in the Dark Green 43102 or 34087 OD. The MK III we have at the USS Ling is in 34102.
JH