/* Safari 4.0 - 8.0 */
@-webkit-keyframes changecolor {
    from {color: linear-gradient(90deg, #18647c 0%, #18647c 30%, #266d82 50%, #3ebee0 80%, #18647c 100%);}
    to {color: red;}
}
/* Standard syntax */
@keyframes changecolor {
    color {color: linear-gradient(90deg, #18647c 0%, #18647c 30%, #266d82 50%, #3ebee0 80%, #18647c 100%);}
    to {color: red;}
}

.scroll span {
  color: linear-gradient(90deg, #18647c 0%, #18647c 30%, #266d82 50%, #3ebee0 80%, #18647c 100%);
  background-size: 200% 100%;
  background-position: 0% 50%;
  -webkit-animation-name: changecolor; /* Safari 4.0 - 8.0 */
  -webkit-animation-duration: 4s; /* Safari 4.0 - 8.0 */
  animation-name: changecolor;
  animation-duration: 4s;

}