edge.blue { color: blue; }
edge.green { color: blue; }
edge.red { color: red; }
group { color: blue; }
group.blue { color: blue; }
group.green { color: blue; }
group.red { color: red; }
node.blue { color: blue; }
node.green { color: blue; }
node.red { color: red; }

[ Black ] { class: green; }
[ Red ] { class: red; }

[ Red ] -- red --> { class: red; } [ Black ]