depending on what time in the halo universe your movie takes place, you may want to have the spartans start out with little/no battle damage and weathering, then have it get worse as movie progresses.
looking cool man, it sounds like you are pretty set on these colors, but i thought i would just let you know in case you are interested, at autozone, they have flat spaypaint specificaly in Camo colors. i think it would definately be awsome if you did want to go for that more desertyl feel.
dang man, good weathering love the sandy look, but there is a definate bold line between the weathered and unweathered part of that shin armor, (i think thats what it is) is that gonna stay like that or is there more weathering to be done, jw