SDD,
What I was saying in my comment was that the premise your question was based on was false. The reason why we see an object as a certain color depends on both the Color of the light shining on it and which colors it reflects back.
For example the reason you see a purple object as purple when you shine a white light on it is because the object absorbs the red light and reflects back the blue and green. Blue and green mixed together makes purple. I you held a piece of plastic over the surface that only let’s green light through (like a transparent green folder) the light reflecting of the surface of the object will appear green.
Your question was assuming that in the case of a purple object the surface of the object was absorbing all of the colors that aren’t purple including green.