テンプレート:テスト2/style.css

.grainbow {
  animation: grainbow .4s linear infinite alternate;
  transition-duration: 1s;
}
@keyframes grainbow {
  0% {color:red}
  20% {color:orange}
  40% {color:yellow}
  60% {color:green}
  80% {color:blue}
  100% {color:purple}
}