changing background in v3dview

In case you need more code, here is the complete init function for the viewing classes.
There is nothing else done with the ais/v3d classes. Changing the background should be straightforward but it isn't. I tried calling various update/redraw functions from the v3dview, and setting default backgrounds with the various functions from the v3dviewer, and absolutely nothing changes.

Aspect_RenderingContext renderingContext = 0;
TCollection_ExtendedString name("Visual3D");
//init v3dviewer
if(this->v3dviewer.IsNull())
{
this->v3dviewer = this->create_viewer("DISPLAY", name.ToExtString(), "", 1000.0);
this->v3dviewer->Init();
this->v3dviewer->SetZBufferManagment(Standard_False);
v3dviewer->SetDefaultTypeOfView(V3d_ORTHOGRAPHIC); //V3d_PERSPECTIVE also possible
this->v3dviewer->SetDefaultViewProj(V3d_Zpos); // Top view
this->v3dviewer->SetUpdateMode(V3d_WAIT);
}
if(this->ais_context.IsNull())
{
this->ais_context = new AIS_InteractiveContext(this->v3dviewer);
this->ais_context->SetHilightColor(Quantity_NOC_WHITE);
}
if(this->v3dview.IsNull())
{
this->v3dview = this->v3dviewer->CreateView();
this->v3dview->SetZClippingType(V3d_OFF);
}

//window
WId id = this->winId();
dfts::integer windowHandle = *reinterpret_cast(&id);
boost::int16_t lo = static_cast(windowHandle);
boost::int16_t hi = static_cast(windowHandle >> 16);
#ifdef WNT
window = new WNT_Window(Handle_Graphic3d_WNTGraphicDevice::DownCast(this->ais_context->CurrentViewer()->Device()),
static_cast(hi), static_cast(lo));
//turn off background erasing in occ window
window->SetFlags(WDF_NOERASEBKGRND);
#else
window = new Xw_Window(Handle_Graphic3d_GraphicDevice::DownCast(this->ais_context->CurrentViewer()->Device()) ,
static_cast(hi), static_cast(lo),
Xw_WQ_SAMEQUALITY, Quantity_NOC_BLACK);
#endif // WNT

if(this->is_null()) { return; }
// set hwnd into the OCC view
this->v3dview->SetWindow(this->window, renderingContext, this->paint_callback, this);
this->v3dview->TriedronDisplay(Aspect_TOTP_LEFT_LOWER, Quantity_NOC_WHITE, 0.1, V3d_ZBUFFER);
this->v3dview->SetScale(viewer_scale);
//
//relevant code for changing background
//
//
this->v3dview->SetBackgroundColor(Quantity_NOC_BLACK);
//
//
//
//
//this->v3dview->SetBgGradientColors (Quantity_Color(0.8,0.8,0.898,Quantity_TOC_RGB), Quantity_Color(0.0,0.0,0.0,Quantity_TOC_RGB), Aspect_GFM_HOR, Standard_False);
if (this->window->IsMapped() == false) { window->Map(); }
this->rubber_band = new QRubberBand(QRubberBand::Rectangle, this);
this->rubber_band->setStyle(new QPlastiqueStyle());