/* the lines within the edges */
.edge:active path,
.edge:hover path {
  stroke: fuchsia;
  stroke-width: 3;
  stroke-opacity: 1;
}
/* arrows are typically drawn with a polygon */
.edge:active polygon,
.edge:hover polygon {
  stroke: fuchsia;
  stroke-width: 3;
  fill: fuchsia;
  stroke-opacity: 1;
  fill-opacity: 1;
}
/* If you happen to have text and want to color that as well... */
.edge:active text,
.edge:hover text {
  fill: fuchsia;
}