I think the coloring page would look great with a mixture of both light and dark shades of green, brown and black. The soldiers could be colored with different variations of green and brown, while the helmets and boots can be colored in a solid black color. The rifles could be colored with all sorts of shades of brown to show their wood grain. The ammo pouches could be colored a mix of both dark and light green along with some black outlines. The sky could be filled with light blue and the ground with a brown or grey color. All in all, it would be a very detailed and visually appealing coloring page!