You could buy camo paint for 3 dollars a can, randomly spray areas, camo paint doesnt mix, so it evenly blends to look....like camo..
I Couldnt find leefy green at any store I went to, paint shop, lows, home depot, big lots, meijers, but I did find army green which is used for a flat effect, or can be combined with other army colors for camo, but it looks the same so I bought it, I also bought sand texture rustoleum paint, it's a tan colored sand texture spray on which I felt would look more detailed for the armor, since in some screenshots you see the cheif's armor uneven. The n ontop of that I will spray my army green and directly whipe it off so only a thin layer is left on which makes the color greenish/tan, then like adam's painting video, I bought some black flat paint, and I will just spray here and there, brush off right away for some more detail.