The layering of the meshes is what refracts the light enough to get the darker look to the glass. I also used a spectral setting which is in the mtl file.
#Produced by Art of Illusion 2.8.1, Fri Nov 05 07:07:54 SGT 2010
newmtl clear
Kd 0.8455 0.8633 0.7654
Ks 0.94 0.82 0.6
Ka 0 0 0
d .312
illum 1
Ns 120
That is the mtl file for the triangle. I used the same texture for all the triangles as I am trying to get rid of the mirror finish, but keep the illumination throughout the layers.
This is the result of the layers with color glass...
This is the result of a test I did with the same mtl settings, but I added a gray texture to the bottom triangle. It didn't turn out so well, so I took out the gray texture for the next test.
This is the last test, with the mtl file settings. I am getting closer to having a frosted look, except for the mirror finish, which I am having trouble removing without removing the light passing through all 3 of the triangles.
You can start to see through the triangles in the last render, but until I can remove the mirror finish without taking away too much light, I have a unique mirror.... [:)] That is what my experiments have produce so far. It's just alot of messing with the mesh, and mtl file of an object.