API Reference > imodeljs-common > Symbology > GeometryParams > backgroundFill backgroundFill backgroundFill: undefined | BackgroundFill Optional fill using the current view background color for region interiors. Valid when GeometryParams.fillDisplay is not FillDisplay.Never and GeometryParams.gradient is undefined. Default is BackgroundFill.None. Defined in core/common/src/GeometryParams.ts Line 91 Last Updated: 13 June, 2024