P element in first div with class="example". Div's index is 0.
P element in first div with class="example color". Div's index is 0.
P element in second div with class="example color". Div's index is 1.
Click the button to change the background color of the first div element with the classes "example" and "color".
Note: The getElementsByClassName() method is not supported in Internet Explorer 8 and earlier versions.