Transparent, but not on background

Is it possible to make a transparency that is not transparent against the background?

In other words, I want to see behind the transparent object, but I don't want the color of the object to be changed when there is nothing (but the background) behind.

Below is a picture to show the idea. On the left, what happens when the object is made transparent (the green object on top, became lighter against the background). This is not what I want.

On the right, what I would like, the green object keeps its original color when against the background. Of course, on the right I cheated, and separated the green object in two ones, by trim and intersect. Then made only the overlapping one transparent.

Thanks