Hello Helo_Joe,
The picture you included as_ gray_/green/black might need to be confirmed before you actually paint.
I've had Crew Chiefs tell me as well as show pictures and they stated it was more of a blue. I tried
to build a kit for a fellow -53 bubba and I used..duck egg blue.. that still needed to be lightened.
The model picture that was sent to you is actually of a Navy hand-me-down, it's a RH-53D in
Marine colors. If you really want to make that kit into a true CH bear in mind you'll need to remove
the refueling probe mount dimple off of the pilot's lower chin bubble window.. as a starter.
How you don't mind this input, if I can help..holler.
Brian