function setBgColor() {
    element.style.backgroundColor = initialBgColor;
  }
Fade elements background color from start color to the element's current
background color.

Start should be a 3D array representing R,G,B

@param {Element} element Dom Node to be used in the animation.
@param {Array<number>} start 3D Array for RGB of start color.
@param {number} time Length of animation in milliseconds.
@param {goog.events.EventHandler=} opt_eventHandler Optional event handler
    to use when listening for events.