I am maintaining an existing application for which I want to start using a custom stylesheet. My first trial only defines the background color for a single widget (combobox pushbutton).

QPushButton#evilButton {
background-color: red;
}

Since I am planning to add many more cases like this I set the stylesheet to the main window.

Now, to my surprise using that simple stylesheet does not only change the color of my button, but also its size and the arrow that marks the combobox option. I have not defined a global QPushButton {...} entry, but my evilButton shape looks clearly different from all the other buttons.

How can I make the above entry to change just the color?