color {
  bounds: 0 0 100 100;
  color: rgb(0,0,0);
}
stroke {
  child: color {
    bounds: 0 0 100 100;
    color: rgb(255,0,0);
  }
  path: "\
M 10 10\
L 90 10\
L 90 90\
L 10 90\
Z";
  line-width: 2;
  line-cap: butt;
  line-join: miter;
}