Yup, what Greg said, had to do the same thing in sniper school...or be seen.
Personally, I don't like black, to distinct of a color, unless operating in the night...which we're not doing in this case.

Don't forget the tops of your ears and the back of your hands if not wearing stuff to cover them.

We used to cover everything just in case we got caught at an inopportune time and didn't have the time to put something over the exposed areas.

It's all personal preference in the end, anything is better than nothing.