I tried the Veloute stain glass tutorial from the Inagoni site and noticed it used a glow for the stain glass to simulate the light making the colors brighter. I turned off the glow and rendered. The stain glass was very dark. It still used transparency to let light through it though. Then I dragged the transparency attributes to the translucency channel and turned off transparency for the stain glass. Here is the render.

www.youtube.com/user/ShawnDriscollCG