1. "The colors of the slices can be set though the CSS. For example, the .default-color0.chart-pie property defines the color of the first slice."

I'm not sure, but filed a bug RT-17086 about absence of fragment in css reference about PieChart. And I also not sure that such option name (.default-color0.chart-pie) is still actual. Usually options in fx2.0 are called "-fx-..." and such name is more suitable for fx1.3. I will explore this question and more clear info about this issue I will add later.

2. "divided into triangular wedges called slices"
 It seems, more suitable word is sectors. (divided into sectors called slices).

3. In "Example 2-1 Creating a Pie Chart"
Add @Override above
    public void start(Stage stage) {