@mixin color-from-animation ($name, $duration, $from, $to) {
  @at-root {
    @include keyframes(color-from-#{$name}) {
      0% { color: $from; }
      100% { color: $to; }
    }
  }
  animation-name: color-from-#{$name};
  animation-iteration-count:  infinite;
  animation-direction: alternate;
  animation-duration: #{$duration}s;
}