title: MUI customize button color?
body: <p>I am struggling to modify button colors in MUI next (v1).</p>
  <p>How would I set muitheme to behave similarity to bootstrap, so I could just use &quot;btn-danger&quot; for red, &quot;btn-success&quot; for green... ?</p>
  <p>I tried with custom <code>className</code> but it doesn't work properly (hover color does't change) and it seems repetitive. What options do I have?</p>