It has taken me a long time to getting around to painting my space marine statue terrain piece. This was in part because I wasn't sure what direction I wanted to take it in.
Eventually, I settled on a rusted, patchy paint scheme as can be seen in the image.
The paint proceeded from a black undercoat following by a gold/bronze mixture base coat. On top of this base coat, I dappled a lot of dull silver in random blobs using a large sized paint brush head. And then a mixture of bronze and silver in other locations.
From there, I used at least three washes of dirty black (basically watered down black mixed with a small amount of brown and red) to settle in to the recesses and give the statue a bit of a dirtier look.
Once dry, I decided that I wanted to have some verdigris on the upper surfaces. Although if the statue were copper, it wouldn't have the dappled silver and gold look, but I still think this technique and look works simply because of the aged look combined with the narrative of "who knows what metal this thing is actually made of!". Its the grim dark of the distant future, after all.
To achieve this look, I painted a zenith (from top down) scatter of dark, forest green on the upper surfaces. This was followed by further washes of a black / green watered down mixture to help it blend in to the other sections.
To finish off, I added black lines in to the recesses to better define the futuristic feeling of the slashes on the arms, as well as the boots and the base. This gives a great "lift" to the overall paint scheme.
I'm half tempted to add a little bit of flock and grass to the statue as well: growing in the recesses where puddles would form after some rain.