.rainbow-text {
  font-size: 42px;
  font-family: Arial Black, Gadget, sans-serif;
  animation: rainbow-color-change 3s linear infinite alternate;
}
@keyframes rainbow-color-change {
  0%,
  100% {
    color: #ff0000;
  } /* Red */
  14% {
    color: #ff8b00;
  } /* Orange */
  28% {
    color: #e8ff00;
  } /* Yellow */
  42% {
    color: #5dff00;
  } /* Green */
  56% {
    color: #00b9ff;
  } /* Blue */
  70% {
    color: #5d00ff;
  } /* Indigo */
  84% {
    color: #e800ff;
  } /* Violet */
}