class ColorChangeEvent : public QCustomEvent

    {

    public:

        ColorChangeEvent( QColor color )

            : QCustomEvent(  ), c( color ) {}

        QColor color() const { return c; }

    private:

        QColor c;

    };

    // To send an event of this custom event type:

    ColorChangeEvent* ce = new ColorChangeEvent( blue );

    QApplication::postEvent( receiver, ce );  // Qt will delete it when done

    // To receive an event of this custom event type:

    void MyWidget::customEvent( QCustomEvent * e )

    {

        if ( e->type() ==  ) {  // It must be a ColorChangeEvent

            ColorChangeEvent* ce = (ColorChangeEvent*)e;

            newColor = ce->color();

        }

    }