Colors and the Mind

Yesterday I was thinking about something that I've always wondered. Does everyone see the same color when they look at an object? For instance, when I look at the grass do I see the same color as the person standing next to me? or do they see what I see when I look at something pink? or purple? or orange? Is my green someone else's red? Maybe our minds recognize the colors differently and we've just learned to identify our mind's interpretation of color by different names. I don't think I'll ever know the answer to my question because how can you test my theory? I don't think there is an answer to these questions but they're interesting to think about.