Depending on your skill something I love the idea of is painting the red underneath then throwing down a layer of chipping medium (or doing whatever your preferred chipping method is) then painting the white over the top.
This is the best example I can find from a quick google search, the idea is that the army have painted their Jacks as they normally would, in a red. This means painting them well as they come off the assembly line, the modeling equivalent of priming, layering, ect, and afterwards varnishing. Then they start marching into a snowy battlefield and begin taking losses. This setting is still more fantasy than diesel punk but is progressing quickly and bright, proud paintjobs might start giving way to practical, modern camouflage. So someone in the Khadorian army gets the bright idea to slap a quick coat of white paint on their Jacks so that next time they go into battle they have the advantage. However in the field you don't have the correct paints and varnishing techniques so you get wear and tear.
You can begin to see the green underneath show through in the tank above, I'd love to see Khador done in the same way with the reds.
