QProgressbar Sınıfı

setStyleSheet metodu
Şöyle yaparız.

QString lStyle = QString("QProgressBar::chunk {background-color: qlineargradient(x1:0,
  y1:0, x2:1, y2:1, stop:0 #b4b4b4, stop:0.1 white, stop:1 #b4b4b4);}");
progressBar->setStyleSheet(lStyle);