The scheme you're referring to on the MH/HH-60G Pave Hawk is based of the Military Airlift Command's version of "European 1" - FS36118 Gray, FS34102 Medium Green and FS34092 Euro 1 Green. Model Master makes all three colors.
There was a variation that replaced the FS34092 with a near-black color. On some machines, it was a total replacement (a 3 color machine) yet on others it was a partial replacement (4 colors used). Look up images of C-5s and C-130s from the 1980s and you may see this color on some of them as well.
These days Pave Hawks are returning from depot level maint. in overall FS36118 gray. During Desert Storm some MH-60Gs flew in a two tone brown scheme and some HH-60Gs of the 305th RQS flew in a new three tone desert scheme. I don't have the FS numbers of the ODS scheme with me right now, but I don't have the new desert scheme FS numbers at all (the colors are similar to desert BDUs, but the darkest brown is lighter than the one on the BDUs)