Here's some information on one of the WW2 Malta history groups.
The pattern, which was only used in Malta, had two main variations;Light vehicles, guns, generators, motorcycles, tanks, etc. which had an irregular outline were painted in a pattern resembling the rubble walls which bordered each and every field. This consisted of shapeless blotches of light stone paint, with a darker colour (dark green or dark brown mostly, but sometimes any dark shade available) between the blotches.Larger vehicles, especially those that had a squarish outline had the stone-coloured paint applied in rectangular blocks to resemble walls of buildings. The darker colour would thus be in straight lines to mimic the mortar and the gaps between the blocks. These vehicles would be parked next to a farmhouse and camouflaged further to resemble an extension of the building.
Malta was awarded the George Cross for not only enduring the heaviest bombing campaign of WW2, but also for taking the fight back to the enemy.
In such a scenario, camouflage was of vital importance for survival. For this reason a camouflage scheme was devised for Malta, and was applied to all equipment destined to be exposed to the enemy. All cars, trucks, motorcycles, field guns, tanks etc. were ‘given the treatment’. Even steel helmets were painted, and not only those used by the services but also those issued to the ARP, the Police, the Public Works, and others.