<div class="wrap">闲看儿童捉柳花</div>

@keyframes move {
  0% {
    background-position: 0 0;
  }
  100% {
    /*宽度固定，如果为百分比背景不会滚动*/
    background-position: -300px 0;
  }
}
.wrap {
  /*设置背景渐变色*/
  background-image: linear-gradient(
    to right,
    red,
    orange,
    yellow,
    green,
    yellow,
    orange,
    red,
    orange,
    yellow,
    green,
    yellow,
    orange,
    red
  );
  /*chrome私有样式，加前缀，文字显示背景图片*/
  -webkit-background-clip: text;
  animation: move 5s infinite;
  /*文字颜色设为透明*/
  color: transparent;
  /*宽度固定*/
  width: 300px;
}