title: How to eliminate hover, active, focus gray color in Material UI Chip component
body: <p>I have Chips implemented in several colors (green, yellow, blue etc.) and by default MUI Chip comes with grey hover/active/focus CSS style. I need to eliminate this hover/active/focus grey background color in MUI Chip component. So once again I don't want to replace gray color with another color but to completely eliminate following CSS styles:</p>
  
  <pre><code>clickable: {
    // Remove grey highlight
    WebkitTapHighlightColor: theme.palette.common.transparent,
    cursor: 'pointer',
    '&amp;:hover, &amp;:focus': {
      backgroundColor: emphasize(backgroundColor, 0.08),
    },
    '&amp;:active': {
      boxShadow: theme.shadows[1],
      backgroundColor: emphasize(backgroundColor, 0.12),
    },
  },
  deletable: {
    '&amp;:focus': {
      backgroundColor: emphasize(backgroundColor, 0.08),
    },
  },
  </code></pre>
  
  <p>In the end this can be done by overriding Chip component in all the colors needed, but there has to be a better way.</p>