Page History
...
Use the Visualization tab's toolbar to assign the visualization that you want.
Make the changes in the Details tab, in the Design tab or in the Source tab.
...
The source code for the visualizations is shown at the bottom of the tab. For more information about using the Source tab refer to Source Tab.
Right-click an object in the tab to open a context menu. The menu items will vary depending on the object which has the focus.
Also Also See
Field Visualizations in the Developer Guide

