I tried this, and it looks like this:
![screen shot 2014-04-13 at 4 35 47 pm](https://cloud.githubusercontent.com/assets/193106/2690514/cc753c38-c34b-11e3-887e-52a0d73f5786.png)
That is not-so-great-looking, and a bit unreadable. I think we're better off not highlighting them.