gistfile1.js

button6.addEventListener('click', function() {
  var red = 'red';
  var halfRed = 'hsla(0, 100%, 25%, 1)';
  var color = thing.style.color;
  if (this.animating === undefined) {
    this.animating = false;
  }
  if (this.animating === true) {
    return;
  }
  this.animating = true;
  thing.style.color = red;
  setTimeout(function() {
    thing.style.color = halfRed;
  }, 500);
  setTimeout(function() {
    thing.style.color = color;
    this.animating = false;
  }.bind(this), 1000);
});