Or the problem that QT uses stylesheet or palette to set the background color

For QT, after setting the background color of a widget, you want the sub-objects to be unaffected. A long time ago I asked a question on qtforum: http://www.qtforum.org/post/94103/setting-background-color-on-widgets-makes-child-widget-wrong-style.html? Highlight = # post94103

There is a similar problem in stackoverflow: http://stackoverflow.com/questions/177778/in-qt-how-do-i-set-the-background-color-of-a-widget-like-combobox-or-double-spin

 

The current method is:

1. If you set the entire dialog box, use the palette

2. If you set an object, use selector.

Class Selector

. Qpushbutton

Matches instances  Qpushbutton , But not of its subclasses. This is equivalent  * [Class ~ = "Qpushbutton"] .

Or

ID  Selector

Qpushbutton # okbutton

Matches all  Qpushbutton   Instances whose  Object Name   Is  Okbutton .