Edit in JSFiddle

(function() {
  var myCanvas =
    document.getElementById("my_canvas");
  var context = myCanvas.getContext("2d");

  //context.translate(150,50);
  // context.rotate(10.Math.PI/180);
  // context.scale(2,2);

  context.fillStyle = "red";
  context.shadowBlur = 10;
  context.shadowColor = "black";
  context.save();
  context.fillRect(50, 50, 100, 50);

  context.fillStyle = "blue";
  context.shadowBlur = 5;
  context.shadowColor = "black";
  context.fillRect(50, 120, 100, 50);

  context.restore();
  context.fillRect(50, 190, 100, 50);

})();

<canvas id="my_canvas" width="300" height="300" style=" border:solid gray 2px;"></canvas>