Great question. The answer is not without controversy however. There are two camps:
#1 - Marine tanks were (in general) painted Marine Green. Photos from different battles indicate that sometimes the tanks were still in factory Olive Drab. And at other times, they appear to be a different shade (greener). So it could come down to the specific battle.
#2 - Marine tanks left the factory in the standard Olive Drab that they all received, and they were not repainted. Why repaint a perfectly good paint job? Now, after combat and damage and all that, and depending on the specific battle, new paint may have been applied. There were certain camo schemes that included a darker green which was applied over an Olive Drab base.
If you go looking for paint sets for WWII Marine Tank models, you will find various sets which include a "Marine Green". Are those sets based on old footage where the colors on the film have degraded to the point people think the tanks were repainted something else? Possibly.
I am of the opinion that Marine tanks in the PTO could be painted the same Olive Drab as Army tanks in the ETO, and you will NOT have made a poor choice. I am not an expect in Marine paint schemes, but having read numerous threads about this, I have not been swayed to the point of view that Marine tanks were painted something different "as a general rule". Camo schemes are different. But just whole-tank paint jobs, I think those were Olive Drab.
