Yea I didn't want to go over the top with the brighness. Here is the entire process:
Entire surface painted p3's bloodstone then a wash of
gw agrax earthshade.
Then the following for the corroded areas:
Stipple black
Stipple Dryad bark
Stipple skrag brown
Stipple skrag brown mixed with wild rider red
Stipple metal colour
Stipple MIG pigment light rust
I don't always include all the steps. I usually miss out the metal as I don't want there to be much metal. Sometimes I use a different brown just to add variation and some are just black then light brown then pigments. Hope this helped