You have demonstrated that philosophers are capable of multiplying entities beyond necessity. Greenness probably corresponds to a behavior of the brain that can be mapped to a specific location. In that sense, and that sense alone, it is objective.
And you wouldn't count the correlation between that location, and a specific range of wavelengths of light, to be objective? Sure you would -- and if you can map that location, then it would be duck soup to show that it really does respond to certain wavelengths of light.
As for the perception experiments you mentioned ... well, your description of the phenomenon shows that you've already identified how the aliasing works.
Doesn't this whole "green" problem boil down to the classic "if a tree falls in the forest and no one's around to hear it" question? In the case of the lonely tree, it certainly falls, and the air vibrates, but "sound" is a reaction in a human brain. No listener, no "sound." Or, to tie this in to the "green" question: no viewer, no green. However, I'm probably missing a bunch of subtleties, as I often do in such discussions.
If color is a behaviour of the brain, then why are people who are color blind still able to see the sky? If it is indeed simply the reaction of our brains to moving electrons, why don't coloblind people have a blank space where things with those colors are?
Our receptors are divided into spatial and light sensitive receptors. If color is objective, then shapes are as well. A blunt object would cut one person, but bounce of another. Balls only roll because we percieve them to roll.
Now does that make sense?