anchor.diff:  }
   
   abstract class OutlinableAction extends Action {
  -  static const LIGHTER_LINE_COLOR = 'rgba(0,0,0,0.3)';
  -  static const DARKER_LINE_COLOR = 'rgba(255,255,255,0.3)';
  +  static const LIGHTER_LINE_COLOR = 'rgba(0,0,0,0.5)';
  +  static const DARKER_LINE_COLOR = 'rgba(255,255,255,0.5)';
   
     static const DASH_INTERVAL = 6;
   
  
positive.code: 
  class FloatLayerAction extends OutlinableAction {
    static const FLOAT_PIXEL_SIZE_FACTOR = 0.85;
  
    final PixelCanvasElement canvas;
    final FloatLayer floatLayer;
  
negative.code: 
              // draw a black cross
              ..beginPath()
              ..strokeStyle = LIGHTER_LINE_COLOR
              ..moveTo(offset.x, offset.y + 1)
              ..lineTo(offset.x + size - 1, offset.y + size)
              ..moveTo(offset.x + size, offset.y + 1)
  