Maybe you know, this control is inherited from standard Button control?
This control have a Handle?
No, it is inherited from TWinControl -> TCustomControl and has a Handle. Its Bitmap.Transparency property is set (by me) to flFuchsia, but transparency does not work… As showed at the first attachement the area around the red circle is lightgray but should be the same color as its owner control (blue). The second attachement shows the TRzBMPButton when skinning is OFF.