How to have a different initial background color for popups shown with <select>?

[deleted312]

I have an application using a QWebEngineView . In this QWebEngineView, I use a <select> to display a popup menu. The application itself and the popup are customized to have a black background color. However when the popup is shown, a white background is initially used: it seems to flash shortly white.

I tried to set an initial black background color to the popup with no success. I made a subclass of QWebEngineView to catch the childEvent events. I was able to get the QEvent::ChildAdded and QEvent::ChildPolished events. I can get the QWidget pointer, however have not been able to change the background color.

void AAAAAAWebEngineView::childEvent(QChildEvent *e)
{
	QWebEngineView::childEvent(e);
	
	if (e->child()->isWidgetType())
	{
		if (e->type() == QEvent::ChildAdded || e->type() == QEvent::ChildPolished)
		{
			QObject *child = e->child();
			QWidget *widget = dynamic_cast<QWidget *>(child);
			if(widget != NULL)
			{
				widget->setStyleSheet("background-color: red;");
			}
		}
	}
}

One of the QWidget I get is a RenderWidgetHostViewQtDelegateWidget with the property m_isPopup set to true, so I guess this is the right QWidget. Trying to change the background color using a style sheet has no effect.

Does anyone know how to set a different initial background color for popups shown with <select>?

[hf81970]

Have you solved this issue? I am facing the same problem.