Saving 3d pictures as anaglyphs

I found [this page](http://arachnoid.com/sage/learning_sage.html) which mentioned (near the bottom) that the Dodecahedral Graph can be rendered in 3D after which you could look at the anaglyph (3D red, cyan image). This picture  is shown (which appears to be Sage output) but I am unable to reproduce it. I tried H=graphs.DodecahedralGraph().plot3d() H.show(stereo='redcyan') H.save("dodec.png") but the resulting png image isn't in 3D. I tried adding **stereo='redcyan'**, **stereo =True**, and other variations to the line saving the png but without success. How do I save anaglyphs like the image above?