gdk:display-is-rgba (display)

display -- a gdk:display object

True if the display supports an alpha channel.

Returns whether surfaces on this display are created with an alpha channel.

Even if a true value is returned, it is possible that the alpha channel of the surface will not be honored when displaying the surface on the screen. In particular, for X an appropriate windowing manager and compositing manager must be running to provide appropriate display. Use the gdk:display-is-composited function to check if that is the case. On modern displays, this value is always true.