Seems to me that there are nuances of "in the wilderness."

For all-out non-observability check into sniper gear and techniques such as ghillie suits.

For being inconspicuous to the authorities in varying circumstances military or even hunting camo might be too troublesome compared to generic greens and browns.
Consider how well your "why no, officer, I ALWAYS wear my LBE and camo my face when I commute to my shift at the 7-11. Why
do you ask?" will go down at the roadblock.

Even the seasonal foliage of that wilderness would matter a lot because background determines what you should be trying to match. (deep snow vs summertime green)

You can buy gray BDU pants and jacket which is a nice unobtrusive color and very functional.

As other posters have noted, practicing the art of staying in shadows, staying still, and being in unexpected elevations helps a lot. Just ask any Bigfoot fan :-)

unimogbert