paper-radio-button.blue::shadow #onRadio {
      background-color: #4285f4;
    }
    
  </style>
  
</head>
<body unresolved>
  
  <section>
    <div class="label">Radio button</div>
    <paper-radio-button></paper-radio-button>
  </section>
  
  <section>
    <div class="label">Radio button (toggles)</div>
    <paper-radio-button toggles></paper-radio-button>
  </section>
  
  <section>
    <div class="label">Radio button (toggles, Blue)</div>
    <paper-radio-button class="blue" toggles></paper-radio-but