clarify legend on home page by restyling

affects page http://todomvc.com/

Before:

![before my fixes (current version)](https://f.cloud.github.com/assets/79168/1090011/8de4cd1c-164e-11e3-910b-d30517cb0f0c.png)

After:

![after my fixes](https://f.cloud.github.com/assets/79168/1090013/95edd44a-164e-11e3-8a7a-745a0b35484a.png)

I made “Maroon” look like what it’s referring to, and I added a border around the legend so it looks different from the app lists.