How to set the background color of a OpenGL enhanced QGraphicsView?

[QAndrew]

I have a custom QGraphicsView class where I try to set the background color in its constructor. These work in non-OpenGL mode:

QColor backgroundColor(50,50,50,255);
setBackGroundBrush(backgroundColor);

and

QPalette myPal = this->palette();
myPal.setColor(this->backgroundRole(), backgroundColor);
this->setPalette(myPal);

However in OpenGL mode the first produces a white screen clearing, while the second clears the widget with the given color. I can also see for a few milliseconds the actual item ought to be drawn in between repaints.

If I don't set the background color at all a white background is set, and everything functions just fine.

[N.Sumi]

'Hi...

If your are working in OPenGL . Then I guess, You can also use

OpenGLFunctions* f = QOpenGLFunctions;
f->glClearColor(0.0f, 0.0f, 0.0f, 0.0f); //Black

[QAndrew]

@N.Sumi
I tried to do this inside my QGraphicsItem::paint() but I get instant crash. I tried with the native brackets and without.

painter->beginNativePainting();
QOpenGLFunctions f;
f.glClearColor(0.0f, 0.0f, 0.0f, 0.0f); //Black
painter->endNativePainting();