Laying off the watering is a good idea for garlic, they can be stressed if there's too much. I had a garlic come up quite yellow last spring, which afterwards became a proper green. That was due to stress- very likely, too much water stress.
My garlic varieties all seem to have a similar shade of green, but I've seen leeks of different shades, and my shallot patch has multiple greens from almost a lime to green-blue. And I think TomNJ mentioned he has a garlic which is a different green than the other as well. So it's always possible that Mexican variety is just different.