CSS rainbow

Chrome only, very easy to port to firefox/IE

.rainbow {
  /* Pretty rainbow colors chrome */
  background: -webkit-gradient(
  linear, left top, left bottom,
  /* red */
  color-stop(0%,rgba(255,50,50,1)),
  color-stop(13%,rgba(255,50,50,1)),
  /* yellow */
  color-stop(14%,rgba(238,255,50,1)),
  color-stop(27%,rgba(255,224,50,1)),
  /* pink */
  color-stop(28%,rgba(255,50,248,1)),
  color-stop(41%,rgba(238,50,255,1)),
  /* green */
  color-stop(42%,rgba(42,201,40,1)),
  color-stop(55%,rgba(0,160,11,1)),
  /* purple */
  color-stop(56%,rgba(122,24,122,1)),
  color-stop(69%,rgba(122,24,122,1)),
  /* orange */
  color-stop(70%,rgba(255,146,50,1)),
  color-stop(83%,rgba(255,139,50,1)),
  /* blue */
  color-stop(84%,rgba(30,87,153,1)),
  color-stop(100%,rgba(30,87,153,1))
  );
}

Apply the rainbow class to your element IE

<div class=rainbow>...