<main class="animateClass" id="animateID">this is animate</main>

.animateClass {
  animation: 3s animate infinite;
}

@keyframes animate {
  from {
    color: red;
  }
  to {
    color: green;
  }
}

#animateID {
  color: blue;
}

main {
  color: gray !important;
}