I'm kinda glad this subject came up and I don't want to burst any bubbles here, but the US Army crews painted pioneer tools (shovel, ax, mattock handle, pick, mattock, tanker bar) the camo color before mounting them (track fixture tools ... track jacks... were left bare metal black). I had to paint all of my basic issue tools back in the 70's on M109's and old guys told me they hated painting tools, just seemed a waste of time.
The Army wants everything to be the camo color to help things blend in on the battle feild and I'm sure there are exceptions when unpainted tools were put on vehicles to replace battle or maneuver damaged ones, or to make a newly issued vehicle look 'new' for a parade. However, the old tradition still stands in the army, paint the pioneer tools.
Paint will wear off when the tool is used, so shovels will have bare metal showing (sometimes with a surprisingly high shine) and will rust if not used frequently. Those are some things to keep in mind when painting pioneer tools.
Hope this helps.
Ron.