как изменить цвет фона QTreeView?

proxyView = new QTreeView;
....
proxyView -> viewport() -> setBackgroundRole (QPalette::Window);
 
QPalette palette (proxyView -> viewport() -> palette());
palette.setBrush (QPalette ::Window, QColor(0,0,0));
proxyView -> viewport() -> setPalette(palette);

QPalette palette (proxyView -> palette());
palette.setBrush (QPalette ::Base QColor(0,0,0));
proxyView -> setPalette(palette);

#include <QtGui>
 
 
int main(int argc, char **argv)
{
    QApplication app(argc, argv);
 
    QMainWindow *window = new QMainWindow();    
    
        window->setWindowTitle(QString::fromUtf8("QTreeWidget Background Color"));
        window->resize(400, 400);
    
    
        QWidget *centralWidget = new QWidget(window);
    QTreeWidget  *tree = new QTreeWidget (centralWidget);
    tree->setFixedSize(395,395);
 
    
    //Set QTreeWidget Column Header
    QTreeWidgetItem* headerItem = new QTreeWidgetItem();
    headerItem->setText(0,QString("Column 1"));
    headerItem->setText(1,QString("Column 2")); 
    tree->setHeaderItem(headerItem);
    
        
    QTreeWidgetItem* item = new QTreeWidgetItem();
    item->setText(0,"item1_1");   
    item->setText(1,"item1_2"); 
    
    
    QPalette* palette = new QPalette();
    palette->setColor(QPalette::Base,Qt::red);  
    tree->setPalette(*(palette));   
    
    tree->addTopLevelItem(item);
    window->setCentralWidget(centralWidget);
    window->show();
    return app.exec();
}