Again, I went for my standard camouflage technique. I did go for smaller patches, which I like for these.
D'oh! I forgot to rust the SPARE tracks on one of these - AND I forgot antenna -- man, I'm slackin'!
To avoid silvering of the decal on the Zimmerit, I applied the decal with water as normal. After that, I took my hobby knife and made holes all around the numbering in the clear areas. This allowed the decal solvent to get behind and solve the silvering problem.

From the Grey Wolf source book from Battlefront Miniatures. Image courtesy of Easy Army.