cross-fade {
  progress: 0.2;
  start: container {
    color {
      bounds: 0 0 10 10;
      color: rgb(255,0,0);
    }
    color {
      bounds: 10 10 10 10;
      color: rgb(0,128,0);
    }
  }
  end: color {
    bounds: 5 5 10 10;
    color: rgb(0,0,255);
  }
}