The display of QColorDialog::getColor dialog is wrong when call the interface with alpha settings.

Try to show a color setting dialog with alpha setting. Then call interface:
QColor QColorDialog::getColor ( const QColor & initial, QWidget * parent, const QString & title, ColorDialogOptions options = 0 ) [static]

Code:
QColor color = QColorDialog::getColor(graphicsScenePaint->currentPen()->color(),
mainWindow,
"Select Color",
QColorDialog::ShowAlphaChannel);

The dialog's display is wrong. See the attachment file's right top corner.