code: function() {
      this.appendDummyInput()
          .appendField(new Blockly.FieldIconMenu(
              [
                {src: Blockly.mainWorkspace.options.pathToMedia + 'icons/set-led_mystery.svg',
                  value: 'mystery', width: 48, height: 48, alt: 'Mystery'},
                {src: Blockly.mainWorkspace.options.pathToMedia + 'icons/set-led_yellow.svg',
                  value: 'yellow', width: 48, height: 48, alt: 'Yellow'},
                {src: Blockly.mainWorkspace.options.pathToMedia + 'icons/set-led_orange.svg',
                  value: 'orange', width: 48, height: 48, alt: 'Orange'},
                {src: Blockly.mainWorkspace.options.pathToMedia + 'icons/set-led_coral.svg',
                  value: 'coral', width: 48, height: 48, alt: 'Coral'},
                {src: Blockly.mainWorkspace.options.pathToMedia + 'icons/set-led_magenta.svg',
                  value: 'magenta', width: 48, height: 48, alt: 'Magenta'},
                {src: Blockly.mainWorkspace.options.pathToMedia + 'icons/set-led_purple.svg',
                  value: 'purple', width: 48, height: 48, alt: 'Purple'},
                {src: Blockly.mainWorkspace.options.pathToMedia + 'icons/set-led_blue.svg',
                  value: 'blue', width: 48, height: 48, alt: 'Blue'},
                {src: Blockly.mainWorkspace.options.pathToMedia + 'icons/set-led_green.svg',
                  value: 'green', width: 48, height: 48, alt: 'Green'},
                {src: Blockly.mainWorkspace.options.pathToMedia + 'icons/set-led_white.svg',
                  value: 'white', width: 48, height: 48, alt: 'White'}
              ]), 'CHOICE');
      this.setOutput(true);
      this.setColour(Blockly.Colours.looks.primary,
          Blockly.Colours.looks.secondary,
          Blockly.Colours.looks.tertiary
      );
    }
docs: Block for set color drop-down (used for shadow).
  @this Blockly.Block