Blue edit of props_2fort/tank001.mdl.
Has 2 skins. Skin 1 is more satured than skin 0.
models/props_2fort/tank001_blue.mdl (and other relevant files)
materials/models/props_2fort/tank001_blue0.vtf + .vmt (skin 0)
materials/models/props_2fort/tank001_blue1.vtf + .vmt (skin 1)
Insert the folder "tank001_blue" in your game's "Team Fortress 2/tf/custom" folder.
By installing it in the custom folder, you can easily delete it later.
Alternativly you can also merge the contents of "tank001_blue" with your tf folder directly.
This method will make it a lot harder to remove later. I do not recommend it.