title: Qt set default value for style-sheet property
body: <p>I have an application where users can modify the Qt stylesheets. I want to set default value for some property in case the user-provided stylesheet does not define them, e.g.</p>
  <pre class="lang-cpp prettyprint-override"><code>// user provided style sheet for the whole app
  qApp-&gt;setStyleSheet(&quot;file://user-provided.qss&quot;);
  
  // default value for my button
  myButton-&gt;setStyleSheet(&quot;color: red&quot;); // I'd like this to apply only if the stylesheet does not provide it
  </code></pre>
  <p>The way Qt cascading works, setting the stylesheet on the widget override anything from the application style-sheet, even if the specifier on the application stylesheet are stronger.</p>
  <p>I tried using <code>QPalette</code>, or different foreground roles with custom color in the <code>.ui</code>, but nothing worked. Unless I use <code>setStyleSheet</code>, the foreground color does not change (as expected since <code>QPalette</code> is ignored when a stylesheet is used).</p>
  <p>Is there a way to have a default value in case a property is missing from the application stylesheet? Basically reverse the cascading effect of Qt?</p>