Colored shadows in Cycles

Hi, I tried to do colored shadows that have a different color from the diffuse base material, but failed. I did the node config from this post
https://blenderartists.org/forum/showthread.php?336509-How-to-change-light-shadow-colour-in-cycles
but it didn’t work at all.

Several comments from this video https://www.youtube.com/watch?v=ALlP3GSrmK4 say that is not even working for them in the 2.7 blender version. Any way to achieve what I’m looking for in Cycles?

Coloured shadows using Light Path node in blender 2.75a


Attachments

coloured_shadows.blend (108 KB)

Thank you, I was missing that light path node. Albeit I noticed that when I did it in my file it wasn’t working, but in your file it was working. So I noticed that I was rendering with the gpu and that was the problem. It seems that gpu rendering can’t render colored shadows with this trick. Do you know a way to get it work for gpu rendering?

just tested it on blender 2.75a, and it works perfectly. make sure the object casting the shadows use this material, and not the plane recieving the shadow.