I remember the days where I used GoonMod's weapon weapon customization feature to paint a few of my guns matte black because they weren't "millitary-grade asssault weapon" looking enough.
You were right, I did enjoy this mod.
What you could do is add options for how saturated the color is, in case the gun looks too dark. Just a suggestion.
Another suggestion is to call this mod "Gun Metal Black" lol.