If the Advanced Vis Config Labs feature is enabled and you have either the Looker Admin role or the can_override_vis_config permission, you can access the Advanced Visualization editor.
Looker visualizations that use the Highcharts API to format their appearance can be customized using this editor. The editor lets you override the value of any of the JSON configuration options of the visualization, which lets you customize aspects of the format and appearance of the visualization. Visualization types that use the Highcharts API include all Cartesian charts, progression charts, pie charts, and word cloud charts.
The Advanced Editor button, which is available from the visualization Edit menu, opens the Advanced Visualization editor, and is demonstrated in this example video clip:
The Chart Config (Source) section displays the visualization JSON configuration options and their values. Click on a collapsed section of the JSON to display details.
The Chart Config (Override) section lets you enter JSON configuration options with custom values.
Click Run to render the visualization with the JSON values that you entered in the Chart Config (Override) section.
Click Copy to copy the JSON in the Chart Config (Override) section to the clipboard.
Click <> to format the JSON in the Chart Config (Override) section.
Click Save to save the values in the Chart Config (Override) section, close the Advanced Editor, and return to the visualization panel in your Explore. The visualization will be displayed using the custom JSON values.