This article helps you to make style sheet in QT.Using this article you can understand how to apply different colors to the Widget and make a stylish widget.
You can select color as Shown in code.you can also replace green and rad color at background.Styles sheets are textual specifications that can be set on the whole application on a specific widget using QWidget::setStyleSheet(). If several style sheets are set at different levels, Qt derives the effective style sheet from all of those that are set. This is called cascading.
Style sheets are applied on top of the current widget style, meaning that your applications will still look native, but any style sheet constraints will be taken into consideration.