anchor.diff:                        buildSizeLabel(18, textStyle),
                         buildSizeLabel(24, textStyle),
                         buildSizeLabel(36, textStyle),
  -                      buildSizeLabel(48, textStyle)
  -                    ]
  +                      buildSizeLabel(48, textStyle),
  +                    ],
                     ),
                     new Expanded(
                       child: new Column(
  
positive.code:                         buildIconButton(18.0, Icons.face, false),
                          buildIconButton(24.0, Icons.alarm, false),
                          buildIconButton(36.0, Icons.home, false),
                          buildIconButton(48.0, Icons.android, false)
                        ]
                      )
                    )
                  ]
                ),
                new Expanded(
                  child: new Center(
                    child: new IconTheme(
                      data: const IconThemeData(opacity: 1.0),
                      child: new Row(
                        mainAxisAlignment: MainAxisAlignment.center,
                        children: <Widget>[
                          new Icon(
                            Icons.brightness_7,
                            color: iconColor.withAlpha(0x33) // 0.2 * 255 = 0x33
                          ),
                          new Slider(
                            value: iconOpacity,
                            min: 0.2,
                            max: 1.0,
                            activeColor: iconColor,
                            onChanged: (double newValue) {
                              setState(() {
                                iconOpacity = newValue;
                              });
                            }
                          ),
                          new Icon(
                            Icons.brightness_7,
                            color: iconColor.withAlpha(0xFF)
                          ),
                        ]
                      )
                    )
                  )
                )
              ]
            )
          )
        )
      );
    }
  }
  
negative.code:                         buildIconButton(18.0, Icons.face, true),
                          buildIconButton(24.0, Icons.alarm, true),
                          buildIconButton(36.0, Icons.home, true),
                          buildIconButton(48.0, Icons.android, true),
                        ],
                      )
                    ),
                    new Expanded(
  