What a beautiful clean build !
I would apply a black wash to the model, and then a flat coat. Then drybrush a slightly lighter shade of the original base green over the entire model, gradually working the shade lighter and lighter.
You can then drybrush a buff colour along the hull sides. I would take good care to drybrush with a virtually clean brush, keep the process very gradual. It will be slow going, and you'll probably ruin a few brushes in the process, but well worth it ;)
Again - great build.