Not only are the histo bars highlighted in Graph Builder, the selected rows will be highlighted in all of the output windows that are open. This is an essential feature of JMP and it allows users to really be able to visualize what is going on in the data. I encourage you to take the time to go to the Help pull down menu in JMP and click on JMP Online Help. On the webpage that pops up, on the left side of the page, there is a selection Discovering JMP. In there you will find items that will give you a real overview of the kinds of things you can do with jmp.
Jim