The color of Qt5 widget is wrong when shown in a Linux vnc session with bgrNNN pixel format

1. create a vnc session on linux with pixel format bgrNNN. For realvnc or tigervnc, you can do: vncserver -pixelformat bgr888. (This pixel format seems to be part of the default setting for some vncserver )

2. run the example attached.

3. click "red" button, you will see the background turns into blue.

This does not happen with Qt4