A childhood belief about eyes

I used to think that people saw the world in their own unique colors. For instance, to me, the grass was green, and what I called green was my own special tint and shade. Someone else, however, may see the grass as the color that I called orange, but to them, orange was green. I wondered if there were some kind of scientific test that could be done to figure this all out. I was going to be the world's greatest scientist LOLOL