Paint.
It wasn’t all that long ago that if you wanted your rifle colored to break up the distinctly black outline of Gene Stoner’s creation, you grabbed a can of Krylon, and did it yourself. Of course, some painful lessons were learned along the way about which parts should not be painted, and how best to keep paint off of those parts. Thanks to the internet, and communities of “gun guys” popping up all over it, some were able to avoid the early pitfalls, and come through the Kryloning of a high dollar investment without many vulgarities escaping our lips.