There must be some rhyme or reason on these maps. However, what that is I am not sure.

As someone else pointed out above, there are a lot of social indexes in there, that's why all the major cities are red. But even red, you can see it down to the neighborhood. Downtown Denver, 16th street mall, is the only red in metro Denver.

But then there is red in Sterling Colorado, theoretically this place is just nailed by hail, etc.

-John