One of the new features called dispersion is a bit tricky to set on first try.  You must select render settings and select the compute physically accurate caustics before you can enable dispersion on the material editor Transparency tab.  Anyway, that one made me scratch my head a bit...

Good to know, Peggy & thanks for the tip.
Now can someone please tell this noob what the beejabbers "dispersion" is?

Hold a prism up to the light - all those pretty colors reflected onto the wall/floor are dispersion. Sort of like caustics, but you see the colors.

Oh!  Now I feel like such a doofus but thanks, Peggy. I refer to this as prismatic reflection, but what do I know?
I always did love that scene with the prisms in Disney's Pollyanna for this very reason.

Stop snickering people.  Weren't you ever a kid?

Dispersion is just the process of refraction when it happens at an angle to a surface (causing light beam bending, so that the white light is separated by frequency because of the frequency dependend electrical properties of the material acting on the electric field of the light). Refraction straight on doesn't bend anything, just changes the speed of the light.

I'd just call it 'refraction' myself. It's confusing to have two terms for the same phenomena. But 'dispersion' seems to be the accept term, according to Wikipedia, and the Wikipedia definition doesn't even mention refraction - weird.

One of my pet peeves is when explanations are self referential, just using scientific names as if the name itself were an explantion of anything - yet never mentioning how any of it WORKS. This definition is a good example of that.
http://en.wikipedia.org/wiki/Dispersion_%28optics%29