How to change QSlider's background color

Question

I would like to change a slider's background color, but this code does not work:

QPalette p( ui->verticalScrollBar->palette());
p.setColor( QPalette::Window, Qt::red );
ui->verticalScrollBar->setPalette(p);

Answer 1

I prefer to use the stylesheet on the Qt controls. This should set the background color to red.

ui->verticalScrollBar->setStyleSheet("QSlider::groove:horizontal {background-color:red;}");

Answer is also here:

QSlider handle is being hidden when changing the background of the groove

Answer 2

Take a look at the Qt documentation, they have an example on customising a QSlider: Qt Style Sheets Examples — Customzing QSlider.

Changing the background property of the CSS class QSlider::groove should do the trick.