window.onload = function () {
  var color = "#8ed1f4"
  // Initialize particleground
  particleground(document.getElementById("particles"), {
    dotColor: color,
    lineColor: color
  });
};

window.onload = function () {
  var color = "#8ed1f4";
  // Initialize particleground
  particleground(document.getElementById("particles"), {
    dotColor: color,
    lineColor: color
  });
};

add missing semicolon