# 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.

# navigator.maskFill

The color of the mask covering the areas of the navigator series that are currently not visible in the main series. The default color is bluish with an opacity of 0.3 to see the series below.