BCGControlBar Pro for MFC
void CBCGPHotSpotImageCtrl::SetBackgroundColor ( COLORREF  color)

Sets background color.

Use this function to set an RGB value to be used by the control's parent when it needs to fill the area around the hot spot image control.

You may need to use background color if the control is placed on a resizable window.

Parameters
colorAn RGB value to set.