QApplication app(argc, argv);
    QWidget w;
    QHBoxLayout hlayout;
    QPixmap pix(98, 98);
    QPainter p(&pix);
    
    pix.fill(Qt::black);
    p.setRenderHint(QPainter::Antialiasing);
    p.setBrush(Qt::gray);
    p.setPen(Qt::NoPen);
    p.drawEllipse(0, 0, pix.width(), pix.height());

    w.setLayout(&hlayout);

    QLabel label1;
    pix.setDevicePixelRatio(1.25);
    label1.setPixmap(pix);
    hlayout.addWidget(&label1);

    QLabel label2;
    pix.setDevicePixelRatio(1);
    label2.setPixmap(pix);
    hlayout.addWidget(&label2);

    w.setPalette(QPalette(Qt::red));
    w.show();