When Canada bought the M151A2 MUTT, they came without a roll cage. Canada later added roll cages that differed from the US ROPS (Roll Over Protection) kit which also had the web netting on the sides.
Usually the vehicles were plain green until about 1970, then the multicolour camouflage was introduced and the markings changed to the subdued style. I have the official camo painting and marking instructions.
You will see pictures of white painted MUTTs in the desert (see link below) but these are earlier flat fender M151 supplied by US to UN and not Canadian purchases (as far as is known).
Some MUTTs were used by Canadians in Vietnam in 1974 with ICCS. These were dark in colour and had a big stripe painted across the hood. I suspect they were supplied "in country" as the US vets would say.
So your basic choice is PERIOD, LOCATION and UNIT.
If you find any markings on your MUTT, RECORD THEM !!!!!!! Even if you chose to paint it to represent another unit of your choice, these markings are usually the ONLY record of the history of vehicle.
Look for the CFR number. It is the KEY identity to your vehicle.
http://www.geocities.com/fordm151/m151cdn.htm
[A good and interesting site but it perpetuates the myth that calls the M151A2 MUTT a "jeep". It is NOT a jeep even though the Canadian Forces and its soldiers often called it a jeep. The MUTT was an independent design that simply resembles a jeep in size and 4x4 but it is not part of the jeep family.