# Welcome to the Highcharts Gantt JS (gantt) Options Reference

These pages outline the chart configuration options, and the methods and properties of Highcharts objects.

Feel free to search this API through the search bar or the navigation tree in the sidebar.

# tooltip.borderColor

The color of the tooltip border. When `undefined`, the border takes the color of the corresponding series or point.

Note that the borderWidth is usually 0 by default, so the border color may not be visible until a border width is set.