That's a pretty good hypothesis. I honestly don't know.

The reason I've preferred purple and (dark) blue is that they only require two properties to have a monopoly, so you can get monopolies sooner. It might be confirmation bias on my part, but my memory is that when I get these monopolies early it often prevents people from developing the orange properties. But like I said, I honestly don't know.

You're probably right that in the long run the orange properties would pay off the most based on being ~7 away from jail, but I wonder if games play out long enough for that to outweigh the effects of getting monopolies early.