A very simple scene: Take a cube, can be the box prop and set the diffuse color to red (255,0,0), specular and ambient color to black.
Now take the one side square prop or another cube and scale it up until is much bigger than the first cube.
Take the first cube and translate it up (ytrans) to the middle of the square prop, then translate it back (ztrans) until is some distance behind the square. You must not see it now.
Set the diffuse color of the square to green (0,255,0), specular and ambient color to black.
Now make the square 100% transparent.
The square is a green glass window and the cube is some object that you want to see through the window.
Render the scene and you will see nothing more than a red cube. Here is the problem!!!!!
The cube cannot be red, it must be black!!!!
You are looking through a green glass and the object has no green component in its color, it is red, so it must look black and never red.

Stupidity also evolves!