WebRectangle.HasBackgroundColor

From Xojo Documentation

Property (As Boolean )
aWebRectangle.HasBackgroundColor = newBooleanValue
or
BooleanValue = aWebRectangle.HasBackgroundColor

New in 2020r1

Supported for all project types and targets.

If True, the color of the rectangle's background is defined by the BackgroundColor property. If False, the color is white.