  
    <!DOCTYPE html>
<html lang="en">
<head>
    <script>
        var colorWell;
        var defaultColor = "#0000ff";

        window.addEventListener("load", startup, false);

        function startup() {
          colorWell = document.querySelector("#colorWell");
          colorWell.value = defaultColor;
          colorWell.addEventListener("input", updateFirst, false);
          colorWell.addEventListener("change", updateAll, false);
          colorWell.select();
        }

        function updateFirst(event) {
          var body  = document.querySelector("body");

          if (body) {
            body.style.background = event.target.value;
          }
        }
        function updateAll(event) {
          document.querySelectorAll("body").forEach(function(body) {
            body.style.background = event.target.value;
          });
        }
    </script>
    </head>
<body>
<input type="color" id="colorWell">
</body>
</html>
  
Colorpicker
