I would assume so, they are both military contracts. I wouldn't see why the USMC wouldn't use green either as that would be appropriate for use in Vietnam.
Possibly what you read was concerning drill sgts. They may have only used khaki. It might also be for today's military as a lot of uniforms went to desert tan instead of green.
I don't know what period your hat devices are for. I thought about getting a USMC one but seemed too complicated figuring out correct period for mine.