"I know what green is."
And for all the rest, you didn't show me.
Bad scientist! ::swats with a nespaper::
If you "know" you can demonstrate it.
All you can demonstrate is that the mind can be fooled. Those are called "illusions"
By spinning a top, it does not become "green" it is still black and white.
Green exists as a universal form, whether you percieve it that way or not is up to you.
It can be argued that if you and I were to swap brains, "green" would become some other color to both of us. This is due to "perception"
"Your" green is not de facto "my" green. HOWEVER: There is a "green" out there that we both percieve AND identify as such. There is a universal idea of "green" just as there is a universal idea of "chair"
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.